Image capturing lens system, image capturing unit and electronic device

ABSTRACT

An image capturing lens system includes three lens groups including five lens elements. The three lens groups are, in order from an object side to an image side: first, second and third lens groups. The five lens elements are, in order from the object side to the image side: first, second, third, fourth and fifth lens elements. The first lens element has an object-side surface being convex in a paraxial region thereof. The second lens element has negative refractive power. At least one lens element has an inflection point. A focal length of the image capturing lens system is varied by changing axial distances between the three lens groups in a zooming process. The image capturing lens system has a long-focal-length end and a short-focal-length end. The second lens group is moved relative to the first lens group along an optical axis in the zooming process.

RELATED APPLICATIONS

This application claims priority to Taiwan Application 109130939, filedon Sep. 9, 2020, which is incorporated by reference herein in itsentirety.

BACKGROUND Technical Field

The present disclosure relates to an image capturing lens system, animage capturing unit and an electronic device, more particularly to animage capturing lens system and an image capturing unit applicable to anelectronic device.

Description of Related Art

With the development of semiconductor manufacturing technology, theperformance of image sensors has improved, and the pixel size thereofhas been scaled down. Therefore, featuring high image quality becomesone of the indispensable features of an optical system nowadays.

Furthermore, due to the rapid changes in technology, electronic devicesequipped with optical systems are trending towards multi-functionalityfor various applications, and therefore the functionality requirementsfor the optical systems have been increasing. However, it is difficultfor a conventional optical system to obtain a balance among therequirements such as high image quality, low sensitivity, a properaperture size, miniaturization and a desirable field of view.

SUMMARY

According to one aspect of the present disclosure, an image capturinglens system includes three lens groups, and the three lens groupsinclude five lens elements. The three lens groups are, in order from anobject side to an image side along an optical path, a first lens group,a second lens group and a third lens group. The five lens elements are,in order from the object side to the image side along the optical path,a first lens element, a second lens element, a third lens element, afourth lens element and a fifth lens element. Each of the five lenselements has an object-side surface facing toward the object side and animage-side surface facing toward the image side.

The first lens group includes the first lens element and the second lenselement, the second lens group includes the third lens element, and thethird lens group includes the fourth lens element and the fifth lenselement. The object-side surface of the first lens element is convex ina paraxial region thereof. The second lens element has negativerefractive power. At least one lens element in the first lens group, thesecond lens group and the third lens group has at least one inflectionpoint in an off-axis region thereof.

A focal length of the image capturing lens system is varied by changingaxial distances between the three lens groups in a zooming process, andthe image capturing lens system has a long-focal-length end and ashort-focal-length end. The second lens group is moved relative to thefirst lens group along an optical axis in the zooming process, and thethird lens group is moved relative to the first lens group along theoptical axis in the zooming process.

When an Abbe number of one of the five lens elements is Vi, a refractiveindex of the one of the five lens elements is Ni, a minimum value ofVi/Ni is (Vi/Ni) min, half of a maximum field of view of the imagecapturing lens system at the short-focal-length end is HFOVS, a maximumdistance between an optically effective area of the object-side surfaceof the first lens element and the optical axis when the image capturinglens system is at the long-focal-length end is Y11L, a maximum distancebetween an optically effective area of the object-side surface of thefirst lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y11S, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the long-focal-length end is Y52L, and a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y52S, the followingconditions are satisfied:

7.5<(Vi/Ni)min<12.3;

5.0 degrees<HFOVS<25.0 degrees;

0.50<Y11L/Y52L<2.0; and

0.50<Y11S/Y52S<2.0.

According to another aspect of the present disclosure, an imagecapturing lens system includes three lens groups, and the three lensgroups include five lens elements. The three lens groups are, in orderfrom an object side to an image side along an optical path, a first lensgroup, a second lens group and a third lens group. The five lenselements are, in order from the object side to the image side along theoptical path, a first lens element, a second lens element, a third lenselement, a fourth lens element and a fifth lens element. Each of thefive lens elements has an object-side surface facing toward the objectside and an image-side surface facing toward the image side.

The object-side surface of the first lens element is convex in aparaxial region thereof. The second lens element has negative refractivepower. At least one lens element in the first lens group, the secondlens group and the third lens group has at least one inflection point inan off-axis region thereof.

A focal length of the image capturing lens system is varied by changingaxial distances between the three lens groups in a zooming process, andthe image capturing lens system has a long-focal-length end and ashort-focal-length end. The second lens group is moved relative to thefirst lens group along an optical axis in the zooming process, and thethird lens group is moved relative to the first lens group along theoptical axis in the zooming process.

When an Abbe number of one of the five lens elements is Vi, a refractiveindex of the one of the five lens elements is Ni, a minimum value ofVi/Ni is (Vi/Ni) min, half of a maximum field of view of the imagecapturing lens system at the short-focal-length end is HFOVS, a maximumdistance between an optically effective area of the object-side surfaceof the first lens element and the optical axis when the image capturinglens system is at the long-focal-length end is Y11L, a maximum distancebetween an optically effective area of the object-side surface of thefirst lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y11S, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the long-focal-length end is Y52L, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y52S, an axial distancebetween the object-side surface of the first lens element and an imagesurface when the image capturing lens system is at the long-focal-lengthend is TLL, and an axial distance between the object-side surface of thefirst lens element and the image surface when the image capturing lenssystem is at the short-focal-length end is TLS, the following conditionsare satisfied:

7.5<(Vi/Ni)min<12.3;

5.0 degrees<HFOVS<25.0 degrees;

0.50<Y11L/Y52L<2.0;

0.50<Y11S/Y52S<2.0; and

|TLL/TLS−1|<1.0E−2.

According to another aspect of the present disclosure, an imagecapturing lens system includes three lens groups, and the three lensgroups include five lens elements. The three lens groups are, in orderfrom an object side to an image side along an optical path, a first lensgroup, a second lens group and a third lens group. The five lenselements are, in order from the object side to the image side along theoptical path, a first lens element, a second lens element, a third lenselement, a fourth lens element and a fifth lens element. Each of thefive lens elements has an object-side surface facing toward the objectside and an image-side surface facing toward the image side.

The object-side surface of the first lens element is convex in aparaxial region thereof. The second lens element has negative refractivepower. At least one lens element in the first lens group, the secondlens group and the third lens group has at least one inflection point inan off-axis region thereof.

A focal length of the image capturing lens system is varied by changingaxial distances between the three lens groups in a zooming process, andthe image capturing lens system has a long-focal-length end and ashort-focal-length end. The second lens group is moved relative to thefirst lens group along an optical axis in the zooming process.

When an Abbe number of one of the five lens elements is Vi, a refractiveindex of the one of the five lens elements is Ni, a minimum value ofVi/Ni is (Vi/Ni) min, half of a maximum field of view of the imagecapturing lens system at the short-focal-length end is HFOVS, a maximumdistance between an optically effective area of the object-side surfaceof the first lens element and the optical axis when the image capturinglens system is at the long-focal-length end is Y11L, a maximum distancebetween an optically effective area of the object-side surface of thefirst lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y11S, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the long-focal-length end is Y52L, and a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y52S, the followingconditions are satisfied:

-   -   7.5<(Vi/Ni) min<12.3;    -   7.5 degrees<HFOVS<20.0 degrees;    -   0.50<Y11L/Y52L<2.0; and    -   0.50<Y11S/Y52S<2.0.

According to another aspect of the present disclosure, an imagecapturing unit includes one of the aforementioned image capturing lenssystems and an image sensor, wherein the image sensor is disposed on animage surface of the image capturing lens system.

According to another aspect of the present disclosure, an electronicdevice includes at least two image capturing units located on the sameside of the electronic device. The at least two image capturing unitsinclude a first image capturing unit and a second image capturing unit.The first image capturing unit includes one of the aforementioned imagecapturing lens systems and an image sensor disposed on an image surfaceof the image capturing lens system. The second image capturing unitincludes an optical lens assembly and an image sensor disposed on animage surface of the optical lens assembly. In addition, half of amaximum field of view of the second image capturing unit ranges between30 degrees and 60 degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be better understood by reading the followingdetailed description of the embodiments, with reference made to theaccompanying drawings as follows:

FIG. 1 is a schematic view of an image capturing unit at theshort-focal-length end according to the 1st embodiment of the presentdisclosure;

FIG. 2 is a schematic view of the image capturing unit at thelong-focal-length end according to the 1st embodiment of the presentdisclosure;

FIG. 3 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at the short-focal-lengthend according to the 1st embodiment;

FIG. 4 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at long-focal-length endaccording to the 1st embodiment;

FIG. 5 is a schematic view of an image capturing unit at theshort-focal-length end according to the 2nd embodiment of the presentdisclosure;

FIG. 6 is a schematic view of the image capturing unit at thelong-focal-length end according to the 2nd embodiment of the presentdisclosure;

FIG. 7 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at the short-focal-lengthend according to the 2nd embodiment;

FIG. 8 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at long-focal-length endaccording to the 2nd embodiment;

FIG. 9 is a schematic view of an image capturing unit at theshort-focal-length end according to the 3rd embodiment of the presentdisclosure;

FIG. 10 is a schematic view of the image capturing unit at thelong-focal-length end according to the 3rd embodiment of the presentdisclosure;

FIG. 11 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at the short-focal-lengthend according to the 3rd embodiment;

FIG. 12 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at long-focal-length endaccording to the 3rd embodiment;

FIG. 13 is a schematic view of an image capturing unit at theshort-focal-length end according to the 4th embodiment of the presentdisclosure;

FIG. 14 is a schematic view of the image capturing unit at thelong-focal-length end according to the 4th embodiment of the presentdisclosure;

FIG. 15 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at the short-focal-lengthend according to the 4th embodiment;

FIG. 16 shows spherical aberration curves, astigmatic field curves and adistortion curve of the image capturing unit at long-focal-length endaccording to the 4th embodiment;

FIG. 17 is one perspective view of an electronic device according to the5th embodiment of the present disclosure;

FIG. 18 is another perspective view of the electronic device in FIG. 17;

FIG. 19 is a cross-sectional view of two image capturing units of theelectronic device in FIG. 17;

FIG. 20 is a perspective view of an electronic device according to the6th embodiment of the present disclosure;

FIG. 21 shows a schematic view of Y11S, TG12S, TLS, BLS, ImgHS, Y52S andan inflection point and a critical point of the fifth lens elementaccording to the 1st embodiment of the present disclosure;

FIG. 22 shows a schematic view of Y11L, TG12L, TLL, BLL, ImgHL, Y52L,TG1, TG2 and TG3 according to the 1st embodiment of the presentdisclosure;

FIG. 23 shows a schematic view of a configuration of a light-foldingelement in an image capturing lens system according to one embodiment ofthe present disclosure;

FIG. 24 shows a schematic view of another configuration of alight-folding element in an image capturing lens system according to oneembodiment of the present disclosure; and

FIG. 25 shows a schematic view of a configuration of two light-foldingelements in an image capturing lens system according to one embodimentof the present disclosure.

DETAILED DESCRIPTION

An image capturing lens system includes three lens groups, and the threelens groups include five lens elements. The three lens groups are, inorder from an object side to an image side along an optical path, afirst lens group, a second lens group and a third lens group. The fivelens elements are, in order from the object side to the image side alongthe optical path, a first lens element, a second lens element, a thirdlens element, a fourth lens element and a fifth lens element. Each ofthe five lens elements has an object-side surface facing toward theobject side and an image-side surface facing toward the image side. Forinstance, in one aspect, the first lens group includes the first lenselement and the second lens element, the second lens group includes thethird lens element, and the third lens group includes the fourth lenselement and the fifth lens element.

According to the present disclosure, the focal length of the imagecapturing lens system is varied by changing axial distances between thethree lens groups in a zooming process, and the image capturing lenssystem has a long-focal-length end and a short-focal-length end.Therefore, the configuration of three lens groups and five lens elementsis favorable for balancing among the zoom ratio, image quality anddifficulty of assembling. Please refer to FIG. 1 and FIG. 2, which areschematic views of an image capturing unit respectively at theshort-focal-length end and the long-focal-length end according to the1st embodiment of the present disclosure. Moreover, there is no relativemotion between lens elements of one lens group in the zooming process(e.g., there is no relative motion between the lens elements of thefirst lens group). Therefore, it is favorable for simplifying thestructure of the image capturing lens system.

The first lens group includes at least one lens element. Moreover, inone configuration where the first lens group includes two lens elements,it is favorable for reducing the outer diameter at the object side ofthe image capturing lens system and obtaining a telephoto configurationin the image capturing lens system. Moreover, the first lens group canhave negative refractive power. Therefore, it is favorable forincreasing the zoom ratio.

The second lens group includes at least one lens element. Moreover, inone configuration where the second lens group includes one lens element,it is favorable for balancing between the zoom ratio and image quality.Moreover, the second lens group is moved relative to the first lensgroup along an optical axis in the zooming process. Therefore, it isfavorable for minimizing mechanical design restrictions of the imagecapturing lens system. Moreover, when the image capturing lens system ischanging from the short-focal-length end to the long-focal-length endduring the zooming process, the second lens group can be moved along theoptical axis toward the object side relative to the first lens group.Therefore, it is favorable for increasing the zoom ratio. In addition,when the image capturing lens system is changing from thelong-focal-length end to the short-focal-length end during the zoomingprocess, the second lens group can be moved along the optical axistoward the image side relative to the first lens group. Moreover, thesecond lens group can have positive refractive power. Therefore, it isfavorable for increasing the zoom ratio and reducing the outer diameterof the image capturing lens system.

The third lens group includes at least one lens element. Moreover, inone configuration where the third lens group includes two lens elements,it is favorable for providing consistent image quality during thezooming process. Moreover, the third lens group can be moved relative tothe first lens group along the optical axis in the zooming process.Therefore, it is favorable for correcting aberrations generated duringthe zooming process and reducing the variation of the back focal length.Moreover, the image capturing lens system can focus on an object in afocusing process as an object distance varies, and the third lens groupcan be moved relative to the first lens group along the optical axis inthe focusing process. Therefore, it is favorable for reducing themovement of lens groups in the focusing process. Moreover, when theobject distance decreases in the focusing process, the third lens groupcan be moved along the optical axis toward the image side relative tothe first lens group. Therefore, it is favorable for correctingaberrations, such as field curvature, generated during the focusingprocess.

According to the present disclosure, the image capturing lens systemfurther includes an aperture stop, and the aperture stop can be disposedin the second lens group. Therefore, it is favorable for adjusting therelative position of the aperture stop during the zooming process so asto balance the image quality at each focal length of the image capturinglens system.

At least one lens group of the image capturing lens system can be movedalong the optical axis so as to compensate temperature effect.Therefore, it is favorable for reducing the influence of temperaturechange on the image quality, so that the image capturing lens system isapplicable to more applications. Moreover, the third lens group can bemoved relative to the first lens group along the optical axis so as tocompensate temperature effect. Therefore, it is favorable for minimizingthe movement of lens groups.

At least one lens element in the first lens group, the second lens groupand the third lens group can be made of plastic material. Therefore, itis favorable for reducing the system size and weight and increasingimage quality and mass production efficiency. Moreover, there can be atleast two lens elements in the first, second and third lens groups beingmade of plastic material. Moreover, there can be at least three lenselements in the first, second and third lens groups being made ofplastic material. Moreover, there can be at least four lens elements inthe first, second and third lens groups being made of plastic material.

At least one lens element in the first lens group, the second lens groupand the third lens group has at least one inflection point in anoff-axis region thereof. Therefore, it is favorable for increasing theshape variation of the lens element so as to miniaturize the lenselement and improve image quality. Moreover, there can be at least twolens elements in the first, second and third lens groups each having atleast one inflection point in an off-axis region thereof. Moreover,there can be at least three lens elements in the first, second and thirdlens groups each having at least one inflection point in an off-axisregion thereof. Moreover, there can be at least four lens elements inthe first, second and third lens groups each having at least oneinflection point in an off-axis region thereof. Please refer to FIG. 21,which shows a schematic view of the inflection point P of the fifth lenselement 150 according to the 1st embodiment of the present disclosure.The inflection point of the fifth lens element in FIG. 21 is onlyexemplary. In each embodiment, each of the lens elements can have one ormore inflection points in an off-axis region thereof.

At least one lens element in the second lens group and the third lensgroup can have at least one critical point in an off-axis regionthereof. Therefore, it is favorable for further increasing the shapevariation of the lens element so as to miniaturize the image capturinglens system and correct aberrations. Please refer to FIG. 21, whichshows a schematic view of the critical point C of the fifth lens element150 according to the 1st embodiment of the present disclosure. Thecritical point of the fifth lens element in FIG. 21 is only exemplary.In each embodiment, each of the lens elements can have one or morecritical points in an off-axis region thereof.

The object-side surface of the first lens element is convex in aparaxial region thereof. Therefore, it is favorable for increasing thezoom ratio and for light rays at different regions within the field ofview to travel into the image capturing lens system evenly.

The second lens element has negative refractive power. Therefore, it isfavorable for balancing the refractive power at the object side of theimage capturing lens system so as to reduce aberrations such asspherical aberration. The image-side surface of the second lens elementcan be concave in a paraxial region thereof. Therefore, it is favorablefor adjusting the surface shape and refractive power of the second lenselement so as to correct aberrations such as astigmatism.

The third lens element can have positive refractive power. Therefore, itis favorable for increasing the zoom ratio. The object-side surface ofthe third lens element can be convex in a paraxial region thereof.Therefore, it is favorable for adjusting light travelling direction soas to increase the zoom ratio and reduce the outer diameter of the imagecapturing lens system. The image-side surface of the third lens elementcan be convex in a paraxial region thereof. Therefore, it is favorablefor adjusting light travelling direction so as to increase the zoomratio and reduce the outer diameter of the image capturing lens system.

When an Abbe number of the first lens element is V1, an Abbe number ofthe second lens element is V2, an Abbe number of the third lens elementis V3, an Abbe number of the fourth lens element is V4, an Abbe numberof the fifth lens element is V5, a refractive index of the first lenselement is N1, a refractive index of the second lens element is N2, arefractive index of the third lens element is N3, a refractive index ofthe fourth lens element is N4, a refractive index of the fifth lenselement is N5, an Abbe number of one of the five lens elements is Vi, arefractive index of the one of the five lens elements is Ni, and aminimum value of Vi/Ni is (Vi/Ni) min, the following condition issatisfied: 7.5<(Vi/Ni) min<12.3, wherein i=1, 2, 3, 4 or 5. Therefore,it is favorable for providing a proper lens material distribution of theimage capturing lens system so as to reduce the system size and correctaberrations.

When half of a maximum field of view of the image capturing lens systemat the short-focal-length end is HFOVS, the following condition issatisfied: 5.0 degrees<HFOVS<25.0 degrees. Therefore, it is favorablefor adjusting the viewing angle at the short-focal-length end so as toobtain a telephoto configuration for various applications. Moreover, thefollowing condition can also be satisfied: 7.5 degrees<HFOVS<20.0degrees. Moreover, the following condition can also be satisfied: 10.0degrees<HFOVS<15.0 degrees.

When a maximum distance between an optically effective area of theobject-side surface of the first lens element and the optical axis whenthe image capturing lens system is at the long-focal-length end is Y11L,and a maximum distance between an optically effective area of theimage-side surface of the fifth lens element and the optical axis whenthe image capturing lens system is at the long-focal-length end is Y52L,the following condition is satisfied: 0.50<Y11L/Y52L<2.0. Therefore, itis favorable for adjusting light travelling direction so as to balanceamong the size, field of view, zoom ratio and image quality in thezooming process. Moreover, the following condition can also besatisfied: 0.55<Y11L/Y52L<1.8. Please refer to FIG. 22, which shows aschematic view of Y11L and Y52L according to the 1st embodiment of thepresent disclosure. In addition, the image capturing lens system in FIG.22 is at the long-focal-length end.

When a maximum distance between an optically effective area of theobject-side surface of the first lens element and the optical axis whenthe image capturing lens system is at the short-focal-length end isY11S, and a maximum distance between an optically effective area of theimage-side surface of the fifth lens element and the optical axis whenthe image capturing lens system is at the short-focal-length end isY52S, the following condition is satisfied: 0.50<Y11S/Y52S<2.0.Therefore, it is favorable for adjusting light travelling direction soas to balance among the size, field of view, zoom ratio and imagequality in the zooming process. Moreover, the following condition canalso be satisfied: 0.55<Y11S/Y52S<1.8. Please refer to FIG. 21, whichshows a schematic view of Y11S and Y52S according to the 1st embodimentof the present disclosure. In addition, the image capturing lens systemin FIG. 21 is at the short-focal-length end.

When an axial distance between the object-side surface of the first lenselement and an image surface when the image capturing lens system is atthe long-focal-length end is TLL, and an axial distance between theobject-side surface of the first lens element and the image surface whenthe image capturing lens system is at the short-focal-length end is TLS,the following condition can be satisfied: |TLL/TLS−1|<1.0E−2. Therefore,it is favorable for adjusting the lens elements and the image surfacedistribution during the zooming process so as to simplify the structureof the image capturing lens system. Moreover, the following conditioncan also be satisfied: |TLL/TLS−1|<5.0E−3. Moreover, the followingcondition can also be satisfied: |TLL/TLS−1|<3.0E−3. Moreover, thefollowing condition can also be satisfied: |TLL/TLS−1|<1.0E−3. Pleaserefer to FIG. 21 and FIG. 22, which respectively show schematic views ofTLS and TLL according to the 1st embodiment of the present disclosure.

When a focal length of the image capturing lens system at thelong-focal-length end is fL, and a focal length of the image capturinglens system at the short-focal-length end is fS, the following conditioncan be satisfied: 1.45<fL/fS. Therefore, it is favorable for increasingthe zoom ratio for more applications. Moreover, the following conditioncan also be satisfied: 1.95<fL/fS. Moreover, the following condition canalso be satisfied: 2.45<fL/fS. Moreover, the following condition canalso be satisfied: fL/fS<4.45. Therefore, it is favorable for preventingthe zoom ratio from being overly large so as to ensure compact systemsize and high image quality. Moreover, the following condition can alsobe satisfied: fL/fS<3.50. Moreover, the following condition can also besatisfied: fL/fS<3.10. Moreover, the following condition can also besatisfied: 1.45<fL/fS<3.10.

When the Abbe number of the third lens element is V3, and the Abbenumber of the fourth lens element is V4, the following condition can besatisfied: 1.5<V3/V4<5.0. Therefore, it is favorable for the materialsof the third and fourth lens elements to collaborate with each other forcorrecting aberrations such as chromatic aberration. Moreover, thefollowing condition can also be satisfied: 2.0<V3/V4<4.5. Moreover, thefollowing condition can also be satisfied: 2.5<V3/V4<4.0.

When a curvature radius of the object-side surface of the fifth lenselement is R9, and a curvature radius of the image-side surface of thefifth lens element is R10, the following condition can be satisfied:0.10<(R9+R10)/(R9−R10)<5.0. Therefore, it is favorable for adjusting thesurface shape of the fifth lens element so as to adjust the incidentangle of light on the image surface and thus improve the responseefficiency of the image sensor.

When a focal length of the first lens element is f1, and a focal lengthof the second lens element is f2, the following condition can besatisfied: |f2/f1|<1.5. Therefore, it is favorable for the refractivepower of the first and second lens elements to collaborate with eachother so as to increase the zoom ratio. Moreover, the followingcondition can also be satisfied: |f2/f1|<1.0. Moreover, the followingcondition can also be satisfied: |f2/f1|<0.50.

When the focal length of the second lens element is f2, and a focallength of the third lens element is f3, the following condition can besatisfied: −2.0<f2/f3<−0.60. Therefore, it is favorable for balancingthe refractive power distribution of the image capturing lens system soas to correct aberrations. Moreover, the following condition can also besatisfied: −1.7<f2/f3<−0.75.

When the maximum distance between the optically effective area of theobject-side surface of the first lens element and the optical axis whenthe image capturing lens system is at the long-focal-length end is Y11L,and a maximum image height of the image capturing lens system at thelong-focal-length end (which can be half of a diagonal length of aneffective photosensitive area of an image sensor) is ImgHL, thefollowing condition can be satisfied: 0.50<Y11L/ImgHL<2.7. Therefore, itis favorable for adjusting light travelling direction in the zoomingprocess so as to reduce the outer diameter of the image capturing lenssystem, enlarge the image surface, and obtain a telephoto configuration.Moreover, the following condition can also be satisfied:0.80<Y11L/ImgHL<2.2. Please refer to FIG. 22, which shows a schematicview of Y11L and ImgHL according to the 1st embodiment of the presentdisclosure.

When the maximum distance between the optically effective area of theobject-side surface of the first lens element and the optical axis whenthe image capturing lens system is at the short-focal-length end isY11S, and a maximum image height of the image capturing lens system atthe short-focal-length end (which can be half of the diagonal length ofthe effective photosensitive area of the image sensor) is ImgHS, thefollowing condition can be satisfied: 0.50<Y11S/ImgHS<2.7. Therefore, itis favorable for adjusting light travelling direction in the zoomingprocess so as to reduce the outer diameter of the image capturing lenssystem, enlarge the image surface, and obtain a telephoto configuration.Moreover, the following condition can also be satisfied:0.80<Y11S/ImgHS<2.2. Please refer to FIG. 21, which shows a schematicview of Y11S and ImgHS according to the 1st embodiment of the presentdisclosure.

When an axial distance between a most object-side surface and a mostimage-side surface of the first lens group is TG1, and an axial distancebetween a most object-side surface and a most image-side surface of thethird lens group is TG3, the following condition can be satisfied:0.50<TG1/TG3<2.0. Therefore, it is favorable for balancing the lenselements distribution at the object side and image side of the imagecapturing lens system so as to reduce the system size and correctaberrations. Moreover, the following condition can also be satisfied:0.65<TG1/TG3<1.7. Please refer to FIG. 22, which shows a schematic viewof TG1 and TG3 according to the 1st embodiment of the presentdisclosure, wherein the most object-side surface of the first lens groupG1 is the object-side surface 111 of the first lens element 110, themost image-side surface of the first lens group G1 is the image-sidesurface 122 of the second lens element 120, the most object-side surfaceof the third lens group G3 is the object-side surface 141 of the fourthlens element 140, and the most image-side surface of the third lensgroup G3 is the image-side surface 152 of the fifth lens element 150.

When a focal length of the second lens group is fG2, and a focal lengthof the third lens group is fG3, the following condition can besatisfied: |fG2/fG3|<0.60. Therefore, it is favorable for the refractivepower of the second and third lens groups to collaborate with each otherso as to provide more consistent image quality in the zooming process.Moreover, the following condition can also be satisfied: |fG2/fG3|<0.45.Moreover, the following condition can also be satisfied: |fG2/fG3|<0.30.Said focal length of one lens group is a composite focal length of alllens elements in the lens group.

When a focal length of the first lens group is fG1, and the focal lengthof the second lens group is fG2, the following condition can besatisfied: −7.0<fG1/fG2<−0.80. Therefore, it is favorable for adjustingthe refractive power distribution of the lens groups so as to increasethe zoom ratio. Moreover, the following condition can also be satisfied:−5.5<fG1/fG2<−1.0. Moreover, the following condition can also besatisfied: −4.0<fG1/fG2<−1.2.

When the axial distance between the object-side surface of the firstlens element and the image surface when the image capturing lens systemis at the long-focal-length end is TLL, and the maximum image height ofthe image capturing lens system at the long-focal-length end is ImgHL,the following condition can be satisfied: 8.0<TLL/ImgHL<15. Therefore,it is favorable for balancing between the system size and image surfacesize. Please refer to FIG. 22, which shows a schematic view of TLL andImgHL according to the 1st embodiment of the present disclosure.

When the axial distance between the object-side surface of the firstlens element and the image surface when the image capturing lens systemis at the short-focal-length end is TLS, and the maximum image height ofthe image capturing lens system at the short-focal-length end is ImgHS,the following condition can be satisfied: 8.0<TLS/ImgHS<15. Therefore,it is favorable for balancing between the system size and image surfacesize. Please refer to FIG. 21, which shows a schematic view of TLS andImgHS according to the 1st embodiment of the present disclosure.

When an axial distance between the first lens group and the second lensgroup when the image capturing lens system is at the long-focal-lengthend is TG12L, an axial distance between the first lens group and thesecond lens group when the image capturing lens system is at theshort-focal-length end is TG12S, and an axial distance between a mostobject-side surface and a most image-side surface of the second lensgroup is TG2, the following condition can be satisfied:−6.0<(TG12L-TG12S)/TG2<−1.2. Therefore, it is favorable for the firstlens group and the second lens group to collaborate each other duringzooming process so as to increase the zoom ratio. Moreover, thefollowing condition can also be satisfied: −4.0<(TG12L-TG12S)/TG2<−1.4.Please refer to FIG. 21 and FIG. 22, which show schematic views ofTG12S, TG12L and TG2 according to the 1st embodiment of the presentdisclosure, wherein the most object-side surface of the second lensgroup G2 is the object-side surface 131 of the third lens element 130,and the most image-side of the second lens group G2 is the image-sidesurface 132 of the third lens element 130.

When half of a maximum field of view of the image capturing lens systemat the long-focal-length end is HFOVL, the following condition can besatisfied: 3.0 degrees<HFOVL<10.0 degrees. Therefore, it is favorablefor adjusting the field of view of the image capturing lens system atthe long-focal-length end so as to obtain a telephoto configuration forvarious applications.

When the axial distance between the most object-side surface and themost image-side surface of the second lens group is TG2, and the axialdistance between the most object-side surface and the most image-sidesurface of the third lens group is TG3, the following condition can besatisfied: 0.40<TG2/TG3<2.0. Therefore, it is favorable for adjustingthe lens elements distribution so as to provide more consistent imagequality in the zooming process. Moreover, the following condition canalso be satisfied: 0.50<TG2/TG3<1.6.

When the focal length of the third lens group is fG3, an axial distancebetween the image-side surface of the fifth lens element and the imagesurface when the image capturing lens system is at the long-focal-lengthend is BLL, and an axial distance between the image-side surface of thefifth lens element and the image surface when the image capturing lenssystem is at the short-focal-length end is BLS, the following conditioncan be satisfied: fG3/(BLL-BLS)<−1.5. Therefore, it is favorable forcorrecting aberrations generated during the zooming process. Moreover,the following condition can also be satisfied: fG3/(BLL-BLS)<−2.5.Please refer to FIG. 21 and FIG. 22, which respectively show schematicviews of BLS and BLL according to the 1st embodiment of the presentdisclosure.

When a curvature radius of the object-side surface of the third lenselement is R5, and a curvature radius of the image-side surface of thethird lens element is R6, the following condition can be satisfied:−1.0<(R5+R6)/(R5−R6)<0. Therefore, it is favorable for adjusting thesurface shape and refractive power of the third lens element so as toreduce the outer diameter of the image capturing lens system.

When the focal length of the image capturing lens system at theshort-focal-length end is fS, the focal length of the first lens groupis fG1, the focal length of the second lens group is fG2, and the focallength of the third lens group is fG3, at least one of the followingconditions can be satisfied: −1.8<fS/fG1<−0.45; 0.70<fS/fG2<2.4; or−0.70<fS/fG3<0.70. Therefore, it is favorable for adjusting therefractive power distribution when the image capturing lens system is atthe short-focal-length end so as to balance among the system size,viewing angle and image quality. Moreover, at least one of the followingconditions can also be satisfied: −1.2<fS/fG1<−0.50; or 1.0<fS/fG2<2.1.

When the axial distance between the object-side surface of the firstlens element and the image surface when the image capturing lens systemis at the long-focal-length end is TLL, and the focal length of theimage capturing lens system at the long-focal-length end is fL, thefollowing condition can be satisfied: 0.80<TLL/fL<1.8. Therefore, it isfavorable for balancing between the total track length and field of viewof the image capturing lens system at the long-focal-length end.Moreover, the following condition can also be satisfied: 1.0<TLL/fL<1.6.

When an f-number of the image capturing lens system at theshort-focal-length end is FnoS, the following condition can besatisfied: 2.2<FnoS<3.8. Therefore, it is favorable for balancingbetween the depth of field and illuminance of the image capturing lenssystem at the short-focal-length end. Moreover, the following conditioncan also be satisfied: 2.4<FnoS<3.5.

According to the present disclosure, the aforementioned features andconditions can be utilized in numerous combinations so as to achievecorresponding effects.

According to the present disclosure, the lens elements of the imagecapturing lens system can be made of either glass or plastic material.When the lens elements are made of glass material, the refractive powerdistribution of the image capturing lens system may be more flexible,and the influence on imaging caused by external environment temperaturechange may be reduced. The glass lens element can either be made bygrinding or molding. When the lens elements are made of plasticmaterial, the manufacturing costs can be effectively reduced.Furthermore, surfaces of each lens element can be arranged to bespherical or aspheric. Spherical lens elements are simple inmanufacture. Aspheric lens element design allows more control variablesfor eliminating aberrations thereof and reducing the required number oflens elements, and the total track length of the image capturing lenssystem can therefore be effectively shortened. Additionally, theaspheric surfaces may be formed by plastic injection molding or glassmolding.

According to the present disclosure, when a lens surface is aspheric, itmeans that the lens surface has an aspheric shape throughout itsoptically effective area, or a portion(s) thereof.

According to the present disclosure, one or more of the lens elements'material may optionally include an additive which alters the lenselements' transmittance in a specific range of wavelength for areduction in unwanted stray light or colour deviation. For example, theadditive may optionally filter out light in the wavelength range of 600nm to 800 nm to reduce excessive red light and/or near infrared light;or may optionally filter out light in the wavelength range of 350 nm to450 nm to reduce excessive blue light and/or near ultraviolet light frominterfering the final image. The additive may be homogeneously mixedwith a plastic material to be used in manufacturing a mixed-materiallens element by injection molding.

According to the present disclosure, each of an object-side surface andan image-side surface has a paraxial region and an off-axis region. Theparaxial region refers to the region of the surface where light raystravel close to the optical axis, and the off-axis region refers to theregion of the surface away from the paraxial region. Particularly,unless otherwise stated, when the lens element has a convex surface, itindicates that the surface is convex in the paraxial region thereof;when the lens element has a concave surface, it indicates that thesurface is concave in the paraxial region thereof. Moreover, when aregion of refractive power or focus of a lens element is not defined, itindicates that the region of refractive power or focus of the lenselement is in the paraxial region thereof.

According to the present disclosure, an inflection point is a point onthe surface of the lens element at which the surface changes fromconcave to convex, or vice versa. A critical point is a non-axial pointof the lens surface where its tangent is perpendicular to the opticalaxis.

According to the present disclosure, the image surface of the imagecapturing lens system, based on the corresponding image sensor, can beflat or curved, especially a curved surface being concave facing towardsthe object side of the image capturing lens system.

According to the present disclosure, an image correction unit, such as afield flattener, can be optionally disposed between the lens elementclosest to the image side of the image capturing lens system along theoptical path and the image surface for correction of aberrations such asfield curvature. The optical properties of the image correction unit,such as curvature, thickness, index of refraction, position and surfaceshape (convex or concave surface with spherical, aspheric, diffractiveor Fresnel types), can be adjusted according to the design of the imagecapturing unit. In general, a preferable image correction unit is, forexample, a thin transparent element having a concave object-side surfaceand a planar image-side surface, and the thin transparent element isdisposed near the image surface.

According to the present disclosure, at least one light-folding elementcan be optionally disposed between an imaged object and the imagesurface on the imaging optical path, such that the image capturing lenssystem can be more flexible in space arrangement, and therefore thedimensions of an electronic device is not restricted by the total tracklength of the image capturing lens system. Moreover, the at least onelight-folding element can be disposed on the object side of the firstlens element. Moreover, the at least one light-folding element caninclude at least one reflection mirror. Moreover, the at least onelight-folding element can include at least one prism. Moreover, theprism can have refractive power, and the surface of the prism caninclude a non-planar surface, such as spherical surface, asphericsurface, concave surface or convex surface. Therefore, it is favorablefor improving image quality. Specifically, please refer to FIG. 23 andFIG. 24. FIG. 23 shows a schematic view of a configuration of alight-folding element in an image capturing lens system according to oneembodiment of the present disclosure, and FIG. 24 shows a schematic viewof another configuration of a light-folding element in an imagecapturing lens system according to one embodiment of the presentdisclosure. In FIG. 23 and FIG. 24, the image capturing lens system canhave, in order from an imaged object (not shown in figure) to an imagesurface IM along an optical path, a first optical axis OA1, alight-folding element LF and a second optical axis OA2. Thelight-folding element LF can be disposed between the imaged object and alens group LG of the image capturing lens system as shown in FIG. 23 ordisposed between a lens group LG of the image capturing lens system andthe image surface IM as shown in FIG. 24. Furthermore, please refer toFIG. 25, which shows a schematic view of a configuration of twolight-folding elements in an image capturing lens system according toone embodiment of the present disclosure. In FIG. 25, the imagecapturing lens system can have, in order from an imaged object (notshown in figure) to an image surface IM along an optical path, a firstoptical axis OA1, a first light-folding element LF1, a second opticalaxis OA2, a second light-folding element LF2 and a third optical axisOA3. The first light-folding element LF1 is disposed between the imagedobject and a lens group LG of the image capturing lens system, and thesecond light-folding element LF2 is disposed between the lens group LGof the image capturing lens system and the image surface IM. The imagecapturing lens system can be optionally provided with three or morelight-folding elements, and the present disclosure is not limited to thetype, amount and position of the light-folding elements of theembodiments disclosed in the aforementioned figures.

According to the present disclosure, the image capturing lens system caninclude at least one stop, such as an aperture stop, a glare stop or afield stop. Said glare stop or said field stop is set for eliminatingthe stray light and thereby improving image quality thereof.

According to the present disclosure, an aperture stop can be configuredas a front stop or a middle stop. A front stop disposed between animaged object and the first lens element can provide a longer distancebetween an exit pupil of the image capturing lens system and the imagesurface to produce a telecentric effect, and thereby improves theimage-sensing efficiency of an image sensor (for example, CCD or CMOS).A middle stop disposed between the first lens element and the imagesurface is favorable for enlarging the viewing angle of the imagecapturing lens system and thereby provides a wider field of view for thesame.

According to the present disclosure, the image capturing lens system caninclude an aperture control unit. The aperture control unit may be amechanical component or a light modulator, which can control the sizeand shape of the aperture through electricity or electrical signals. Themechanical component can include a movable member, such as a bladeassembly or a light shielding sheet. The light modulator can include ashielding element, such as a filter, an electrochromic material or aliquid-crystal layer. The aperture control unit controls the amount ofincident light or exposure time to enhance the capability of imagequality adjustment. In addition, the aperture control unit can be theaperture stop of the present disclosure, which changes the f-number toobtain different image effects, such as the depth of field or lensspeed.

According to the present disclosure, the object side and image side aredefined in accordance with the direction of the optical axis, and theaxial optical data are calculated along the optical axis. Furthermore,if the optical axis is folded by a light-folding element, the axialoptical data are also calculated along the folded optical axis.

According to the above description of the present disclosure, thefollowing specific embodiments are provided for further explanation.

1ST EMBODIMENT

FIG. 1 is a schematic view of an image capturing unit at theshort-focal-length end according to the 1st embodiment of the presentdisclosure. FIG. 2 is a schematic view of the image capturing unit atthe long-focal-length end according to the 1st embodiment of the presentdisclosure. FIG. 3 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at the short-focal-length end according to the 1stembodiment. FIG. 4 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at long-focal-length end according to the 1stembodiment. In FIG. 1 and FIG. 2, the image capturing unit includes theimage capturing lens system (its reference numeral is omitted) of thepresent disclosure and an image sensor 180. The image capturing lenssystem includes, in order from an object side to an image side along anoptical path, a stop 101, a first lens element 110, a second lenselement 120, an aperture stop 100, a third lens element 130, a fourthlens element 140, a fifth lens element 150, a filter 160 and an imagesurface 170. In addition, the image capturing lens system has aconfiguration of a first lens group G1 including the first lens element110 and the second lens element 120, a second lens group G2 includingthe aperture stop 100 and the third lens element 130, and a third lensgroup G3 including the fourth lens element 140 and the fifth lenselement 150. The first lens group G1 has negative refractive power, thesecond lens group G2 has positive refractive power, and the third lensgroup G3 has negative refractive power. The image capturing lens systemincludes five lens elements (110, 120, 130, 140, and 150) with noadditional lens element disposed between each of the adjacent five lenselements.

The focal length of the image capturing lens system is varied bychanging axial distances between the three lens groups (G1, G2, and G3)in a zooming process. As shown in FIG. 1 and FIG. 2, the second lensgroup G2 is moved relative to the first lens group G1 along an opticalaxis in the zooming process, and the third lens group G3 is movedrelative to the first lens group G1 along the optical axis in thezooming process. Furthermore, the image capturing lens system has ashort-focal-length end as shown in FIG. 1 and a long-focal-length end asshown in FIG. 2. In addition, when the image capturing lens system ischanging from the short-focal-length end to the long-focal-length endduring the zooming process, the second lens group G2 is moved along theoptical axis toward the object side relative to the first lens group G1.It is noted that there is no relative motion between lens elements ofeach of the three lens groups in the zooming process.

The first lens element 110 with positive refractive power has anobject-side surface 111 being convex in a paraxial region thereof and animage-side surface 112 being convex in a paraxial region thereof. Thefirst lens element 110 is made of plastic material and has theobject-side surface 111 and the image-side surface 112 being bothaspheric. The first lens element 110 has at least one inflection pointin an off-axis region thereof.

The second lens element 120 with negative refractive power has anobject-side surface 121 being concave in a paraxial region thereof andan image-side surface 122 being concave in a paraxial region thereof.The second lens element 120 is made of plastic material and has theobject-side surface 121 and the image-side surface 122 being bothaspheric.

The third lens element 130 with positive refractive power has anobject-side surface 131 being convex in a paraxial region thereof and animage-side surface 132 being convex in a paraxial region thereof. Thethird lens element 130 is made of plastic material and has theobject-side surface 131 and the image-side surface 132 being bothaspheric. The third lens element 130 has at least one inflection pointin an off-axis region thereof.

The fourth lens element 140 with negative refractive power has anobject-side surface 141 being concave in a paraxial region thereof andan image-side surface 142 being concave in a paraxial region thereof.The fourth lens element 140 is made of plastic material and has theobject-side surface 141 and the image-side surface 142 being bothaspheric. The fourth lens element 140 has at least one inflection pointin an off-axis region thereof.

The fifth lens element 150 with positive refractive power has anobject-side surface 151 being convex in a paraxial region thereof and animage-side surface 152 being convex in a paraxial region thereof. Thefifth lens element 150 is made of plastic material and has theobject-side surface 151 and the image-side surface 152 being bothaspheric. The fifth lens element 150 has at least one inflection pointand at least one critical point in an off-axis region thereof.

The filter 160 is made of glass material and located between the fifthlens element 150 and the image surface 170, and will not affect thefocal length of the image capturing lens system. The image sensor 180 isdisposed on or near the image surface 170.

The equation of the aspheric surface profiles of the aforementioned lenselements of the 1st embodiment is expressed as follows:

${{X(Y)} = {{\left( {Y^{2}\text{/}R} \right)\text{/}\left( {1 + {{sqrt}\left( {1 - {\left( {1 + k} \right) \times \left( {Y\text{/}R} \right)^{2}}} \right)}} \right)} + {\sum\limits_{i}{({Ai}) \times \left( Y^{i} \right)}}}},$

where,

X is a displacement in parallel with an optical axis from an axialvertex on the aspheric surface to a point at a distance of Y from theoptical axis on the aspheric surface;

Y is the vertical distance from the point on the aspheric surface to theoptical axis;

R is the curvature radius;

k is the conic coefficient; and

Ai is the i-th aspheric coefficient, and in the embodiments, i may be,but is not limited to, 4, 6, 8, 10, 12, 14 and 16.

In the image capturing lens system of the image capturing unit accordingto the 1st embodiment, a focal length of the image capturing lens systemis f, an f-number of the image capturing lens system is Fno, half of amaximum field of view of the image capturing lens system is HFOV, anaxial distance between an imaged object and the stop 101 is D0, an axialdistance between the second lens element 120 and the aperture stop 100is D5, an axial distance between the third lens element 130 and thefourth lens element 140 is D8, and an axial distance between the filter160 and the image surface 170 is D14. With different focusingconditions, the aforementioned parameters may have different values. Inthis embodiment, two of various focusing states of the image capturinglens system according to different focusing conditions are provided(i.e., different object distances). A first focusing state of the imagecapturing lens system is a state where the image capturing lens systemfocuses on an imaged object located at infinity, and a second focusingstate of the image capturing lens system is a state where the imagecapturing lens system focuses on an imaged object located at a finitedistance.

Furthermore, in each focusing state, some of the aforementionedparameters have different values when the image capturing lens system isat the short-focal-length end or at the long-focal-length end.Specifically, a focal length of the image capturing lens system at theshort-focal-length end is fS, a focal length of the image capturing lenssystem at the long-focal-length end is fL, an f-number of the imagecapturing lens system at the short-focal-length end is FnoS, an f-numberof the image capturing lens system at the long-focal-length end is FnoL,half of a maximum field of view of the image capturing lens system atthe short-focal-length end is HFOVS, and half of a maximum field of viewof the image capturing lens system at the long-focal-length end isHFOVL.

Note that FIG. 1 shows the image capturing lens system at theshort-focal-length end in the first focusing state, and FIG. 2 shows theimage capturing lens system at the long-focal-length end in the firstfocusing state.

In the first focusing state, when the image capturing lens system is atthe short-focal-length end, the aforementioned parameters have thefollowing values: fS=7.50 millimeters (mm), FnoS=2.92, HFOVS=13.1degrees (deg.), D0=∞ (infinity), D5=5.787 mm, D8=0.400 mm, and D14=4.786mm.

In the first focusing state, when the image capturing lens system is atthe long-focal-length end, the aforementioned parameters have thefollowing values: fL=18.75 mm, FnoL=4.45, HFOVL=5.3 degrees, D0=∞,D5=0.594 mm, D8=0.886 mm, and D14=9.500 mm.

When a focal length of the first lens group G1 is fG1, a focal length ofthe second lens group G2 is fG2, and a focal length of the third lensgroup G3 is fG3, the following conditions are satisfied: fG1=−10.69 mm;fG2=3.94 mm; and fG3=−17.03 mm.

When an Abbe number of the first lens element 110 is V1, an Abbe numberof the second lens element 120 is V2, an Abbe number of the third lenselement 130 is V3, an Abbe number of the fourth lens element 140 is V4,an Abbe number of the fifth lens element 150 is V5, an Abbe number ofthe i-th lens element is Vi, a refractive index of the first lenselement 110 is N1, a refractive index of the second lens element 120 isN2, a refractive index of the third lens element 130 is N3, a refractiveindex of the fourth lens element 140 is N4, a refractive index of thefifth lens element 150 is N5, a refractive index of the i-th lenselement is Ni, and a minimum value of Vi/Ni is (Vi/Ni) min, thefollowing condition is satisfied: (Vi/Ni) min=10.90, wherein i=1, 2, 3,4, or 5. In this embodiment, among the first through fifth lens elements(110-150), a ratio of the Abbe number and the refractive index of thefourth lens element 140 is equal to a ratio of the Abbe number and therefractive index of the fifth lens element 150 and smaller than that ofthe other lens elements, and (Vi/Ni) min is equal to the ratio of theAbbe number and the refractive index of the fourth lens element 140 andthe ratio of the Abbe number and the refractive index of the fifth lenselement 150.

When the Abbe number of the third lens element 130 is V3, and the Abbenumber of the fourth lens element 140 is V4, the following condition issatisfied: V3/V4=3.05.

When an axial distance between the first lens group G1 and the secondlens group G2 when the image capturing lens system is at thelong-focal-length end is TG12L, an axial distance between the first lensgroup G1 and the second lens group G2 when the image capturing lenssystem is at the short-focal-length end is TG12S, and an axial distancebetween a most object-side surface and a most image-side surface of thesecond lens group G2 is TG2, the following condition is satisfied:(TG12L-TG12S)/TG2=−2.08.

When an axial distance between the object-side surface 111 of the firstlens element 110 and the image surface 170 when the image capturing lenssystem is at the long-focal-length end is TLL, and an axial distancebetween the object-side surface 111 of the first lens element 110 andthe image surface 170 when the image capturing lens system is at theshort-focal-length end is TLS, the following condition is satisfied:|TLL/TLS−1|=3.54E−04.

When an axial distance between a most object-side surface and a mostimage-side surface of the first lens group G1 is TG1, and an axialdistance between a most object-side surface and a most image-sidesurface of the third lens group G3 is TG3, the following condition issatisfied: TG1/TG3=1.39.

When the axial distance between the most object-side surface and themost image-side surface of the second lens group G2 is TG2, and theaxial distance between the most object-side surface and the mostimage-side surface of the third lens group G3 is TG3, the followingcondition is satisfied: TG2/TG3=0.90.

When the axial distance between the object-side surface 111 of the firstlens element 110 and the image surface 170 when the image capturing lenssystem is at the long-focal-length end is TLL, and the focal length ofthe image capturing lens system at the long-focal-length end is fL, thefollowing condition is satisfied: TLL/fL=1.12.

When the axial distance between the object-side surface 111 of the firstlens element 110 and the image surface 170 when the image capturing lenssystem is at the long-focal-length end is TLL, and a maximum imageheight of the image capturing lens system at the long-focal-length endis ImgHL, the following condition is satisfied: TLL/ImgHL=11.99.

When the axial distance between the object-side surface 111 of the firstlens element 110 and the image surface 170 when the image capturing lenssystem is at the short-focal-length end is TLS, and a maximum imageheight of the image capturing lens system at the short-focal-length endis ImgHS, the following condition is satisfied: TLS/ImgHS=11.99.

When a curvature radius of the object-side surface 131 of the third lenselement 130 is R5, and a curvature radius of the image-side surface 132of the third lens element 130 is R6, the following condition issatisfied: (R5+R6)/(R5−R6)=−0.16.

When a curvature radius of the object-side surface 151 of the fifth lenselement 150 is R9, and a curvature radius of the image-side surface 152of the fifth lens element 150 is R10, the following condition issatisfied: (R9+R10)/(R9−R10)=0.23.

When a focal length of the first lens element 110 is f1, and a focallength of the second lens element 120 is f2, the following condition issatisfied: |f2/f1|=0.37.

When the focal length of the second lens group G2 is fG2, and the focallength of the third lens group G3 is fG3, the following condition issatisfied: |fG2/fG3|=0.23.

When the focal length of the second lens element 120 is f2, and a focallength of the third lens element 130 is f3, the following condition issatisfied: f2/f3=−0.89.

When the focal length of the first lens group G1 is fG1, and the focallength of the second lens group G2 is fG2, the following condition issatisfied: fG1/fG2=−2.71.

When the focal length of the third lens group G3 is fG3, an axialdistance between the image-side surface 152 of the fifth lens element150 and the image surface 170 when the image capturing lens system is atthe long-focal-length end is BLL, and an axial distance between theimage-side surface 152 of the fifth lens element 150 and the imagesurface 170 when the image capturing lens system is at theshort-focal-length end is BLS, the following condition is satisfied:fG3/(BLL-BLS)=−3.61.

When the focal length of the image capturing lens system at thelong-focal-length end is fL, and the focal length of the image capturinglens system at the short-focal-length end is fS, the following conditionis satisfied: fL/fS=2.50.

When the focal length of the image capturing lens system at theshort-focal-length end is fS, the focal length of the first lens groupG1 is fG1, the focal length of the second lens group G2 is fG2, and thefocal length of the third lens group G3 is fG3, the following conditionsare satisfied: fS/fG1=−0.70; fS/fG2=1.90; and fS/fG3=−0.44.

When a maximum distance between an optically effective area of theobject-side surface 111 of the first lens element 110 and the opticalaxis when the image capturing lens system is at the long-focal-lengthend is Y11L, and the maximum image height of the image capturing lenssystem at the long-focal-length end is ImgHL, the following condition issatisfied: Y11L/ImgHL=1.50.

When the maximum distance between the optically effective area of theobject-side surface 111 of the first lens element 110 and the opticalaxis when the image capturing lens system is at the long-focal-lengthend is Y11L, and a maximum distance between an optically effective areaof the image-side surface 152 of the fifth lens element 150 and theoptical axis when the image capturing lens system is at thelong-focal-length end is Y52L, the following condition is satisfied:Y11L/Y52L=1.46.

When a maximum distance between an optically effective area of theobject-side surface 111 of the first lens element 110 and the opticalaxis when the image capturing lens system is at the short-focal-lengthend is Y11S, and the maximum image height of the image capturing lenssystem at the short-focal-length end is ImgHS, the following conditionis satisfied: Y11S/ImgHS=1.71.

When the maximum distance between the optically effective area of theobject-side surface 111 of the first lens element 110 and the opticalaxis when the image capturing lens system is at the short-focal-lengthend is Y11S, and a maximum distance between an optically effective areaof the image-side surface 152 of the fifth lens element 150 and theoptical axis when the image capturing lens system is at theshort-focal-length end is Y52S, the following condition is satisfied:Y11S/Y52S=1.64.

The detailed optical data of the 1st embodiment are shown in Table 1 andTable 2, and the aspheric surface data are shown in Table 3 below.

TABLE 1 1st Embodiment Surface # Curvature Radius Thickness MaterialIndex Abbe # Focal Length 0 Object Plano D0 1 Stop Plano −0.515 2 Lens 112.730 (ASP) 1.232 Plastic 1.545 56.1 9.43 3 −8.322 (ASP) 2.290 4 Lens 2−46.085 (ASP) 0.372 Plastic 1.544 56.0 −3.50 5 1.992 (ASP) D5 6 Ape.Stop Plano −0.394 7 Lens 3 3.272 (ASP) 2.502 Plastic 1.544 56.0 3.94 8−4.542 (ASP) D8 9 Lens 4 −4.198 (ASP) 0.542 Plastic 1.686 18.4 −5.42 1034.259 (ASP) 1.397 11 Lens 5 19.082 (ASP) 0.854 Plastic 1.686 18.4 10.8812 −12.033 (ASP) 1.000 13 Filter Plano 0.210 Glass 1.517 64.2 — 14 Plano D14 15 Image Plano — Note: Reference wavelength is 587.6 nm (d-line).An effective radius of the stop 101 (Surface 1) is 3.000 mm.

In Table 1, the curvature radius, the thickness and the focal length areshown in millimeters (mm). Surface numbers 0-15 represent the surfacessequentially arranged from the object side to the image side along theoptical axis.

The rest optical data of the image capturing lens system, including inthe second focusing state, are disclosed in Table 2 below. Also, thedefinitions of the parameters shown in Table 2 are consistent with thosestated in the first focusing state. Furthermore, in each focusing state,one of various zooming states between the short-focal-length end and thelong-focal-length end of the image capturing lens system andcorresponding optical data are also disclosed in this embodiment. Inaddition, it can be known from Table 2 that when the object distancedecreases in the focusing process (e.g., from the first focusing stateto the second focusing state), the axial distance between the first lensgroup G1 and the third lens group G3 increases from, for example, 8.295mm (at the short-focal-length end) and 3.588 mm (at thelong-focal-length end) of the first focusing state to 8.322 mm (at theshort-focal-length end) and 3.704 mm (at the long-focal-length end) ofthe second focusing state; that is, when the object distance decreasesin the focusing process, the third lens group G3 is moved along theoptical axis toward the image side relative to the first lens group G1in the focusing process.

TABLE 2 1st Embodiment First Focusing State Short-focal- Long-focal-length End length End f [mm] 7.50 13.13 18.75 fG1 [mm] −10.69 |f2/f1|0.37 Fno 2.92 3.78 4.45 fG2 [mm] 3.94 |fG2/fG3| 0.23 HFOV 13.1 7.6 5.3fG3 [mm] −17.03 f2/f3 −0.89 [deg.] D0 [mm] ∞ ∞ ∞ (Vi/Ni)min 10.90fG1/fG2 −2.71 D5 [mm] 5.787 2.322 0.594 V3/V4 3.05 fG3/(BLL − BLS) −3.61D8 [mm] 0.400 0.200 0.886 (TG12L − TG12S)/TG2 −2.08 fL/fS 2.50 D14 [mm]4.786 8.446 9.500 |TLL/TLS − 1| 3.54E−04 fS/fG1 −0.70 Second FocusingState TG1/TG3 1.39 fS/fG2 1.90 Short-focal- Long-focal- TG2/TG3 0.90fS/fG3 −0.44 length End length End Fno 2.93 3.80 4.49 TLL/fL 1.12Y11L/ImgHL 1.50 HFOV 13.1 7.5 5.3 TLL/ImgHL 11.99 Y11L/Y52L 1.46 [deg.]D0 [mm] 1000.000 1000.000 1000.000 TLS/ImgHS 11.99 Y11S/ImgHS 1.71 D5[mm] 5.787 2.322 0.594 (R5 + R6)/(R5 − R6) −0.16 Y11S/Y52S 1.64 D8 [mm]0.427 0.262 1.002 (R9 + R10)/(R9 − R10) 0.23 — — D14 [mm] 4.761 8.3849.389 — — — —

TABLE 3 Aspheric Coefficients Surface # 2 3 4 5 7 k = 0.0000E+000.0000E+00 0.0000E+00 0.0000E+00  0.0000E+00 A4 = 3.2047E−03 7.1078E−03−7.6190E−02  −1.1372E−01  −4.2790E−03 A6 = −1.9268E−04  −8.6847E−04 4.5462E−02 5.6887E−02  1.3359E−03 A8 = 3.8338E−05 1.6573E−04−2.1017E−02  −2.9369E−02  −1.3549E−03 A10 = −2.6068E−06  −2.2900E−05 6.5079E−03 9.7107E−03  7.8283E−04 A12 = −3.2172E−08  1.7386E−06−1.1826E−03  −1.9181E−03  −2.3273E−04 A14 = 1.1975E−08 −5.0355E−08 9.4223E−05 1.5461E−04  2.8475E−05 A16 = — — — — −3.4129E−07 Surface # 89 10 11 12 k = 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A4= 7.0203E−03 6.3622E−02 7.0316E−02 1.6736E−02 7.1574E−03 A6 = 3.8251E−03−3.4629E−02  −3.7496E−02  −1.1716E−02  −4.9477E−03  A8 = −6.4021E−03 1.4537E−02 1.7154E−02 5.8994E−03 1.0448E−03 A10 = 5.2091E−03−4.2245E−03  −7.8850E−03  −3.2712E−03  −2.2425E−04  A12 = −2.3084E−03 7.7101E−04 3.1222E−03 1.1961E−03 −3.4020E−06  A14 = 5.3734E−04−6.4609E−05  −7.9131E−04  −2.6000E−04  3.2643E−06 A16 = −5.1060E−05  —8.7752E−05 2.3273E−05 —

In Table 3, k represents the conic coefficient of the equation of theaspheric surface profiles. A4-A16 represent the aspheric coefficientsranging from the 4th order to the 16th order. The tables presented belowfor each embodiment are the corresponding schematic parameter andaberration curves, and the definitions of the tables are the same asTable 1 to Table 3 of the 1st embodiment. Therefore, an explanation inthis regard will not be provided again.

2ND EMBODIMENT

FIG. 5 is a schematic view of an image capturing unit at theshort-focal-length end according to the 2nd embodiment of the presentdisclosure. FIG. 6 is a schematic view of the image capturing unit atthe long-focal-length end according to the 2nd embodiment of the presentdisclosure. FIG. 7 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at the short-focal-length end according to the 2ndembodiment. FIG. 8 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at long-focal-length end according to the 2ndembodiment. In FIG. 5 and FIG. 6, the image capturing unit includes theimage capturing lens system (its reference numeral is omitted) of thepresent disclosure and an image sensor 280. The image capturing lenssystem includes, in order from an object side to an image side along anoptical path, a stop 201, a first lens element 210, a second lenselement 220, an aperture stop 200, a third lens element 230, a fourthlens element 240, a fifth lens element 250, a filter 260 and an imagesurface 270. In addition, the image capturing lens system has aconfiguration of a first lens group G1 including the first lens element210 and the second lens element 220, a second lens group G2 includingthe aperture stop 200 and the third lens element 230, and a third lensgroup G3 including the fourth lens element 240 and the fifth lenselement 250. The first lens group G1 has negative refractive power, thesecond lens group G2 has positive refractive power, and the third lensgroup G3 has negative refractive power. The image capturing lens systemincludes five lens elements (210, 220, 230, 240, and 250) with noadditional lens element disposed between each of the adjacent five lenselements.

The focal length of the image capturing lens system is varied bychanging axial distances between the three lens groups (G1, G2, and G3)in a zooming process. As shown in FIG. 5 and FIG. 6, the second lensgroup G2 is moved relative to the first lens group G1 along an opticalaxis in the zooming process, and the third lens group G3 is movedrelative to the first lens group G1 along the optical axis in thezooming process. Furthermore, the image capturing lens system has ashort-focal-length end as shown in FIG. 5 and a long-focal-length end asshown in FIG. 6. In addition, when the image capturing lens system iszooming from the short-focal-length end to the long-focal-length end,the second lens group G2 is moved along the optical axis toward theobject side relative to the first lens group G1. It is noted that thereis no relative motion between lens elements of each of the three lensgroups in the zooming process.

The first lens element 210 with positive refractive power has anobject-side surface 211 being convex in a paraxial region thereof and animage-side surface 212 being convex in a paraxial region thereof. Thefirst lens element 210 is made of plastic material and has theobject-side surface 211 and the image-side surface 212 being bothaspheric. The first lens element 210 has at least one inflection pointin an off-axis region thereof.

The second lens element 220 with negative refractive power has anobject-side surface 221 being concave in a paraxial region thereof andan image-side surface 222 being concave in a paraxial region thereof.The second lens element 220 is made of plastic material and has theobject-side surface 221 and the image-side surface 222 being bothaspheric.

The third lens element 230 with positive refractive power has anobject-side surface 231 being convex in a paraxial region thereof and animage-side surface 232 being convex in a paraxial region thereof. Thethird lens element 230 is made of glass material and has the object-sidesurface 231 and the image-side surface 232 being both aspheric. Thethird lens element 230 has at least one inflection point and at leastone critical point in an off-axis region thereof.

The fourth lens element 240 with positive refractive power has anobject-side surface 241 being concave in a paraxial region thereof andan image-side surface 242 being convex in a paraxial region thereof. Thefourth lens element 240 is made of plastic material and has theobject-side surface 241 and the image-side surface 242 being bothaspheric. The fourth lens element 240 has at least one inflection pointin an off-axis region thereof.

The fifth lens element 250 with negative refractive power has anobject-side surface 251 being convex in a paraxial region thereof and animage-side surface 252 being concave in a paraxial region thereof. Thefifth lens element 250 is made of plastic material and has theobject-side surface 251 and the image-side surface 252 being bothaspheric. The fifth lens element 250 has at least one inflection pointand at least one critical point in an off-axis region thereof.

The filter 260 is made of glass material and located between the fifthlens element 250 and the image surface 270, and will not affect thefocal length of the image capturing lens system. The image sensor 280 isdisposed on or near the image surface 270.

In this embodiment, one of various focusing states of the imagecapturing lens system is provided, and the focusing state of the imagecapturing lens system is a state where the image capturing lens systemfocuses on an imaged object located at infinity.

The detailed optical data of the 2nd embodiment are shown in Table 4 andTable 5, and the aspheric surface data are shown in Table 6 below.

TABLE 4 2nd Embodiment Surface # Curvature Radius Thickness MaterialIndex Abbe # Focal Length 0 Object Plano Infinity 1 Stop Plano −0.414 2Lens 1 9.844 (ASP) 2.200 Plastic 1.639 23.5 9.86 3 −15.940 (ASP) 1.970 4Lens 2 −58.482 (ASP) 0.710 Plastic 1.650 21.8 −4.08 5 2.792 (ASP) D5 6Ape. Stop Plano −0.370 7 Lens 3 3.299 (ASP) 2.027 Glass 1.569 71.3 4.588 −9.634 (ASP) D8 9 Lens 4 −4.161 (ASP) 2.800 Plastic 1.701 14.8 22.0310 −4.187 (ASP) 0.050 11 Lens 5 8.370 (ASP) 0.706 Plastic 1.544 56.0−15.83 12 4.119 (ASP) 1.000 13 Filter Plano 0.210 Glass 1.517 64.2 — 14Plano  D14 15 Image Plano — Note: Reference wavelength is 587.6 nm(d-line). An effective radius of the stop 201 (Surface 1) is 2.980 mm.

The definitions of these parameters shown in Table 5 are the same asthose stated in the 1st embodiment with corresponding values for the 2ndembodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 4 and Table 6 asthe following values and satisfy the following conditions:

TABLE 5 2nd Embodiment Short-focal- Long-focal- length End length End f[mm] 8.30 16.71 fG1 [mm] −15.87 |f2/f1| 0.41 Fno 2.58 3.67 fG2 [mm] 4.58|fG2/fG3| 0.15 HFOV [deg.] 11.9 6.0 fG3 [mm] −30.86 f2/f3 −0.89 D5 [mm]5.034 0.420 (Vi/Ni)min 8.70 fG1/fG2 −3.47 D8 [mm] 2.767 0.450 V3/V4 4.82fG3/(BLL − BLS) −4.45 D14 [mm] 0.503 7.442 (TG12L − TG12S)/TG2 −2.28fL/fS 2.01 |TLL/TLS − 1| 4.28E−04 fS/fG1 −0.52 TG1/TG3 1.37 fS/fG2 1.81TG2/TG3 0.57 fS/fG3 −0.27 TLL/fL 1.17 Y11L/ImgHL 1.64 TLL/ImgHL 11.21Y11L/Y52L 1.63 TLS/ImgHS 11.20 Y11S/ImgHS 1.69 (R5 + R6)/(R5 − R6) −0.49Y11S/Y52S 1.71 (R9 + R10)/(R9 − R10) 2.94 — —

In the 2nd embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment, so an explanation in this regard will not be provided again.

TABLE 6 Aspheric Coefficients Surface # 2 3 4 5 7 k = 2.1440E+00−1.2164E+01 9.0000E+01 −3.9660E−01  1.8245E+00 A4 = 1.1343E−03 4.5782E−03 −6.1112E−03  −1.9055E−02 −5.5965E−03 A6 = −4.3882E−05 −4.2809E−04 −1.0422E−03  −1.1592E−03 −2.6679E−03 A8 = 5.6591E−06 4.9721E−05 5.1482E−04  1.8142E−03  2.3114E−03 A10 = −2.3459E−07 −3.9202E−06 −8.9962E−05  −8.2999E−04 −1.5740E−03 A12 = —  1.1627E−076.2505E−07  1.9367E−04  4.7261E−04 A14 = — — 1.0890E−06 −1.8211E−05−6.2386E−05 Surface # 8 9 10 11 12 k = −1.6278E+00 4.0028E−01 2.1170E−01−2.7724E+01 −8.3275E+00 A4 =  8.5408E−03 1.5154E−02 2.6656E−03−4.9761E−02 −4.7982E−02 A6 = −8.6474E−04 −4.0856E−03  −2.8539E−03 −1.4010E−03  6.7439E−03 A8 =  2.0500E−03 2.9620E−03 3.0350E−03 3.3701E−03 −7.3148E−04 A10 = −1.0850E−03 −1.6111E−03  −1.8618E−03 −1.7942E−03  7.6516E−05 A12 =  3.0891E−04 5.7328E−04 6.5153E−04 4.9744E−04 −2.2494E−05 A14 = −2.9893E−05 −1.0918E−04  −1.1641E−04 −5.5854E−05  5.4062E−06 A16 = — 9.0760E−06 8.2554E−06 −3.9480E−07−6.2228E−07

3RD EMBODIMENT

FIG. 9 is a schematic view of an image capturing unit at theshort-focal-length end according to the 3rd embodiment of the presentdisclosure. FIG. 10 is a schematic view of the image capturing unit atthe long-focal-length end according to the 3rd embodiment of the presentdisclosure. FIG. 11 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at the short-focal-length end according to the 3rdembodiment. FIG. 12 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at long-focal-length end according to the 3rdembodiment. In FIG. 9 and FIG. 10, the image capturing unit includes theimage capturing lens system (its reference numeral is omitted) of thepresent disclosure and an image sensor 380. The image capturing lenssystem includes, in order from an object side to an image side along anoptical path, a first lens element 310, a second lens element 320, athird lens element 330, an aperture stop 300, a fourth lens element 340,a fifth lens element 350, a filter 360 and an image surface 370. Inaddition, the image capturing lens system has a configuration of a firstlens group G1 including the first lens element 310 and the second lenselement 320, a second lens group G2 including the third lens element 330and the aperture stop 300, and a third lens group G3 including thefourth lens element 340 and the fifth lens element 350. The first lensgroup G1 has negative refractive power, the second lens group G2 haspositive refractive power, and the third lens group G3 has positiverefractive power. The image capturing lens system includes five lenselements (310, 320, 330, 340, and 350) with no additional lens elementdisposed between each of the adjacent five lens elements.

The focal length of the image capturing lens system is varied bychanging axial distances between the three lens groups (G1, G2, and G3)in a zooming process. As shown in FIG. 9 and FIG. 10, the second lensgroup G2 is moved relative to the first lens group G1 along an opticalaxis in the zooming process, and the third lens group G3 is movedrelative to the first lens group G1 along the optical axis in thezooming process. Furthermore, the image capturing lens system has ashort-focal-length end as shown in FIG. 9 and a long-focal-length end asshown in FIG. 10. In addition, when the image capturing lens system iszooming from the short-focal-length end to the long-focal-length end,the second lens group G2 is moved along the optical axis toward theobject side relative to the first lens group G1. It is noted that thereis no relative motion between lens elements of each of the three lensgroups in the zooming process.

The first lens element 310 with positive refractive power has anobject-side surface 311 being convex in a paraxial region thereof and animage-side surface 312 being concave in a paraxial region thereof. Thefirst lens element 310 is made of plastic material and has theobject-side surface 311 and the image-side surface 312 being bothaspheric. The first lens element 310 has at least one inflection pointin an off-axis region thereof.

The second lens element 320 with negative refractive power has anobject-side surface 321 being convex in a paraxial region thereof and animage-side surface 322 being concave in a paraxial region thereof. Thesecond lens element 320 is made of plastic material and has theobject-side surface 321 and the image-side surface 322 being bothaspheric. The second lens element 320 has at least one inflection pointin an off-axis region thereof.

The third lens element 330 with positive refractive power has anobject-side surface 331 being convex in a paraxial region thereof and animage-side surface 332 being convex in a paraxial region thereof. Thethird lens element 330 is made of plastic material and has theobject-side surface 331 and the image-side surface 332 being bothaspheric. The third lens element 330 has at least one inflection pointin an off-axis region thereof.

The fourth lens element 340 with negative refractive power has anobject-side surface 341 being concave in a paraxial region thereof andan image-side surface 342 being concave in a paraxial region thereof.The fourth lens element 340 is made of plastic material and has theobject-side surface 341 and the image-side surface 342 being bothaspheric. The fourth lens element 340 has at least one inflection pointand at least one critical point in an off-axis region thereof.

The fifth lens element 350 with positive refractive power has anobject-side surface 351 being concave in a paraxial region thereof andan image-side surface 352 being convex in a paraxial region thereof. Thefifth lens element 350 is made of plastic material and has theobject-side surface 351 and the image-side surface 352 being bothaspheric. The fifth lens element 350 has at least one inflection pointin an off-axis region thereof.

The filter 360 is made of glass material and located between the fifthlens element 350 and the image surface 370, and will not affect thefocal length of the image capturing lens system. The image sensor 380 isdisposed on or near the image surface 370.

In this embodiment, one of various focusing states of the imagecapturing lens system is provided, and the focusing state of the imagecapturing lens system is a state where the image capturing lens systemfocuses on an imaged object located at infinity.

The detailed optical data of the 3rd embodiment are shown in Table 7 andTable 8, and the aspheric surface data are shown in Table 9 below. Inthis embodiment, an axial distance between the second lens element 320and the third lens element 330 is D4, an axial distance between theaperture stop 300 and the fourth lens element 340 is D7, and an axialdistance between the filter 360 and the image surface 370 is D13.

TABLE 7 3rd Embodiment Surface # Curvature Radius Thickness MaterialIndex Abbe # Focal Length 0 Object Plano Infinity 1 Lens 1 4.472 (ASP)0.800 Plastic 1.545 56.1 25.19 2 6.215 (ASP) 0.074 3 Lens 2 3.594 (ASP)0.900 Plastic 1.587 28.3 −6.91 4 1.729 (ASP) D4 5 Lens 3 5.206 (ASP)1.744 Plastic 1.544 56.0 7.02 6 −12.633 (ASP) −0.020 7 Ape. Stop PlanoD7 8 Lens 4 −16.945 (ASP) 1.000 Plastic 1.669 19.5 −7.76 9 7.666 (ASP)0.227 10 Lens 5 −13.530 (ASP) 1.000 Plastic 1.544 56.0 7.03 11 −3.059(ASP) 0.500 12 Filter Plano 0.210 Glass 1.517 64.2 — 13 Plano  D13 14Image Plano — Note: Reference wavelength is 587.6 nm (d-line).

The definitions of these parameters shown in Table 8 are the same asthose stated in the 1st embodiment with corresponding values for the 3rdembodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 7 and Table 9 asthe following values and satisfy the following conditions:

TABLE 8 3rd Embodiment Short-focal- Long-focal- length End length End f[mm] 8.51 17.00 fG1 [mm] −11.38 |f2/f1| 0.27 Fno 3.05 4.55 fG2 [mm] 7.02|fG2/fG3| 0.25 HFOV [deg.] 13.7 6.9 fG3 [mm] 27.95 f2/f3 −0.98 D4 [mm]6.227 2.484 (Vi/Ni)min 11.65 fG1/fG2 −1.62 D7 [mm] 5.056 13.110 V3/V42.88 fG3/(BLL − BLS) −6.49 D13 [mm] 5.286 0.981 (TG12L − TG12S)/TG2−2.15 fL/fS 2.00 |TLL/TLS − 1| 2.23E−04 fS/fG1 −0.75 TG1/TG3 0.80 fS/fG21.21 TG2/TG3 0.78 fS/fG3 0.30 TLL/fL 1.35 Y11L/ImgHL 1.17 TLL/ImgHL11.28 Y11L/Y52L 1.12 TLS/ImgHS 11.28 Y11S/ImgHS 1.40 (R5 + R6)/(R5 − R6)−0.42 Y11S/Y52S 1.27 (R9 + R10)/(R9 − R10) 1.58 — —

In the 3rd embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment, so an explanation in this regard will not be provided again.

TABLE 9 Aspheric Coefficients Surface # 1 2 3 4 5 k = −1.8080E+00−1.8716E−02 −2.2343E+00 −1.6674E+00  2.8397E+00 A4 =  8.5525E−04 2.4496E−03 −8.6620E−03 −7.0849E−03 −2.5280E−03 A6 = −1.9241E−04 1.8622E−04  1.7153E−03  1.0049E−03 −2.8330E−05 A8 = −4.1025E−06−1.2454E−06 −1.3819E−04 −3.8075E−06 −9.1157E−05 A10 = −2.1704E−06−6.3046E−06  3.2530E−05 −3.8365E−05  3.6043E−05 A12 = −3.8218E−08−3.6511E−07 −1.3231E−05  1.0204E−05 −1.0256E−05 A14 =  3.9027E−09−6.7652E−08  2.6463E−06 −1.3637E−06  1.4821E−06 A16 =  1.2853E−09−1.6299E−09 −2.8629E−07  6.8695E−08 −1.0046E−07 A18 = —  1.3231E−09 1.2491E−08 — — Surface # 6 8 9 10 11 k = −8.0494E+01  5.0000E+00−6.9986E+01 −6.2362E+01 −5.2428E+00 A4 = −3.7709E−03 −1.8585E−02 1.3837E−02  1.8408E−02 −1.2763E−02 A6 =  1.4539E−03 −2.7613E−03−1.8018E−02 −9.7685E−03  6.5829E−04 A8 = −3.9902E−04  2.4406E−03 6.7447E−03  1.4557E−03  1.6555E−03 A10 =  1.1911E−04 −6.9649E−04−1.4084E−03  3.3874E−04 −9.0256E−04 A12 = −2.3765E−05  1.0151E−04 1.5930E−04 −1.4676E−04  2.5159E−04 A14 =  2.8158E−06 −5.5754E−06−7.3197E−06  1.9395E−05 −3.4681E−05 A16 = −1.3604E−07 — — −9.5792E−07 1.8135E−06

4TH EMBODIMENT

FIG. 13 is a schematic view of an image capturing unit at theshort-focal-length end according to the 4th embodiment of the presentdisclosure. FIG. 14 is a schematic view of the image capturing unit atthe long-focal-length end according to the 4th embodiment of the presentdisclosure. FIG. 15 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at the short-focal-length end according to the 4thembodiment. FIG. 16 shows, in order from left to right, sphericalaberration curves, astigmatic field curves and a distortion curve of theimage capturing unit at long-focal-length end according to the 4thembodiment. In FIG. 13 and FIG. 14, the image capturing unit includesthe image capturing lens system (its reference numeral is omitted) ofthe present disclosure and an image sensor 480. The image capturing lenssystem includes, in order from an object side to an image side along anoptical path, a stop 401, a reflective prism 490, a first lens element410, a second lens element 420, a third lens element 430, an aperturestop 400, a fourth lens element 440, a fifth lens element 450, a filter460 and an image surface 470. In addition, the image capturing lenssystem has a configuration of a first lens group G1 including the firstlens element 410 and the second lens element 420, a second lens group G2including the third lens element 430 and the aperture stop 400, and athird lens group G3 including the fourth lens element 440 and the fifthlens element 450. The first lens group G1 has negative refractive power,the second lens group G2 has positive refractive power, and the thirdlens group G3 has positive refractive power. The image capturing lenssystem includes five lens elements (410, 420, 430, 440, and 450) with noadditional lens element disposed between each of the adjacent five lenselements.

The focal length of the image capturing lens system is varied bychanging axial distances between the three lens groups (G1, G2, and G3)in a zooming process. As shown in FIG. 13 and FIG. 14, the second lensgroup G2 is moved relative to the first lens group G1 along an opticalaxis in the zooming process, and the third lens group G3 is movedrelative to the first lens group G1 along the optical axis in thezooming process. Furthermore, the image capturing lens system has ashort-focal-length end as shown in FIG. 13 and a long-focal-length endas shown in FIG. 14. In addition, when the image capturing lens systemis zooming from the short-focal-length end to the long-focal-length end,the second lens group G2 is moved along the optical axis toward theobject side relative to the first lens group G1. It is noted that thereis no relative motion between lens elements of each of the three lensgroups in the zooming process.

The reflective prism 490 with positive refractive power has anobject-side surface 491 being concave in a paraxial region thereof andan image-side surface 492 being convex in a paraxial region thereof. Thereflective prism 490 is made of plastic material and has the object-sidesurface 491 and the image-side surface 492 being both aspheric. Thereflective prism 490 is a light-folding element configured forreflecting incident light, such that the optical path is deflected atthe reflective prism 490.

The first lens element 410 with negative refractive power has anobject-side surface 411 being convex in a paraxial region thereof and animage-side surface 412 being concave in a paraxial region thereof. Thefirst lens element 410 is made of plastic material and has theobject-side surface 411 and the image-side surface 412 being bothaspheric. The first lens element 410 has at least one inflection pointin an off-axis region thereof.

The second lens element 420 with negative refractive power has anobject-side surface 421 being convex in a paraxial region thereof and animage-side surface 422 being concave in a paraxial region thereof. Thesecond lens element 420 is made of plastic material and has theobject-side surface 421 and the image-side surface 422 being bothaspheric. The second lens element 420 has at least one inflection pointin an off-axis region thereof.

The third lens element 430 with positive refractive power has anobject-side surface 431 being convex in a paraxial region thereof and animage-side surface 432 being convex in a paraxial region thereof. Thethird lens element 430 is made of plastic material and has theobject-side surface 431 and the image-side surface 432 being bothaspheric.

The fourth lens element 440 with negative refractive power has anobject-side surface 441 being convex in a paraxial region thereof and animage-side surface 442 being concave in a paraxial region thereof. Thefourth lens element 440 is made of plastic material and has theobject-side surface 441 and the image-side surface 442 being bothaspheric. The fourth lens element 440 has at least one inflection pointand at least one critical point in an off-axis region thereof.

The fifth lens element 450 with positive refractive power has anobject-side surface 451 being concave in a paraxial region thereof andan image-side surface 452 being convex in a paraxial region thereof. Thefifth lens element 450 is made of plastic material and has theobject-side surface 451 and the image-side surface 452 being bothaspheric. The fifth lens element 450 has at least one inflection pointand at least one critical point in an off-axis region thereof.

The filter 460 is made of glass material and located between the fifthlens element 450 and the image surface 470, and will not affect thefocal length of the image capturing lens system. The image sensor 480 isdisposed on or near the image surface 470.

In this embodiment, one of various focusing states of the imagecapturing lens system is provided, and the focusing state of the imagecapturing lens system is a state where the image capturing lens systemfocuses on an imaged object located at infinity.

The detailed optical data of the 4th embodiment are shown in Table 10and Table 11, and the aspheric surface data are shown in Table 12 below.In this embodiment, an axial distance between the second lens element420 and the third lens element 430 is D7′, an axial distance between theaperture stop 400 and the fourth lens element 440 is D10, and an axialdistance between the filter 460 and the image surface 470 is D16.

TABLE 10 4th Embodiment Surface # Curvature Radius Thickness MaterialIndex Abbe # Focal Length 0 Object Plano Infinity 1 Stop Plano 0.029 2Reflective −298.841 (ASP) 6.133 Plastic 1.534 56.0 162.21 Prism 3−67.663 (ASP) 0.077 4 Lens 1 4.673 (ASP) 1.104 Plastic 1.545 56.1−123.15 5 4.005 (ASP) 0.104 6 Lens 2 2.917 (ASP) 0.584 Plastic 1.63923.3 −9.60 7 1.823 (ASP) D7′  8 Lens 3 5.294 (ASP) 2.500 Plastic 1.54456.0 6.78 9 −10.129 (ASP) −0.076 10 Ape. Stop Plano D10 11 Lens 4 50.741(ASP) 1.000 Plastic 1.679 18.4 −7.50 12 4.590 (ASP) 0.227 13 Lens 5−13.213 (ASP) 0.898 Plastic 1.544 56.0 7.32 14 −3.134 (ASP) 0.500 15Filter Plano 0.210 Glass 1.517 64.2 — 16 Plano D16 17 Image Plano —Note: Reference wavelength is 587.6 nm (d-line). An effective radius ofthe stop 401 (Surface 1) is 3.000 mm.

The definitions of these parameters shown in Table 11 are the same asthose stated in the 1st embodiment with corresponding values for the 4thembodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 10 and Table 12as the following values and satisfy the following conditions:

TABLE 11 4th Embodiment Short-focal- Long-focal- length End length End f[mm] 8.00 16.00 fG1 [mm] −9.55 |f2/f1| 0.08 Fno 2.93 4.41 fG2 [mm] 6.78|fG2/fG3| 0.13 HFOV [deg.] 14.6 7.3 fG3 [mm] 50.80 f2/f3 −1.42 D7′ [mm]6.253 2.237 (Vi/Ni)min 10.98 fG1/fG2 −1.41 D10 [mm] 4.418 12.743 V3/V43.04 fG3/(BLL − BLS) −11.79 D16 [mm] 5.283 0.974 (TG12L − TG12S)/TG2−1.61 fL/fS 2.00 |TLL/TLS − 1| 1.49E−05 fS/fG1 −0.84 TG1/TG3 0.84 fS/fG21.18 TG2/TG3 1.18 fS/fG3 0.16 TLL/fL 1.44 Y11L/ImgHL 1.17 TLL/ImgHL11.28 Y11L/Y52L 1.17 TLS/ImgHS 11.28 Y11S/ImgHS 1.14 (R5 + R6)/(R5 − R6)−0.31 Y11S/Y52S 1.12 (R9 + R10)/(R9 − R10) 1.62 — —

In the 4th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment, so an explanation in this regard will not be provided again.

TABLE 12 Aspheric Coefficients Surface # 2 3 4 5 6 7 k =  0.0000E+000.0000E+00 −2.1261E+00  −3.5827E−01 −2.3021E+00 −1.7406E+00 A4 =−1.1092E−04 4.8876E−04 4.8486E−04  2.0411E−03 −7.3301E−03 −9.5186E−03 A6=  1.3770E−05 4.9794E−05 −3.0193E−04  −1.4178E−05  2.5739E−03 2.7212E−03 A8 = −6.9661E−07 −1.2500E−05  8.3063E−07 −5.3669E−05−4.8347E−04 −8.9803E−04 A10 = — — 7.4086E−07 −1.5023E−05 −1.7654E−05 2.4090E−04 A12 = — — 3.9336E−07 −1.4033E−06  2.7185E−05 −8.0331E−05 A14= — — 1.4769E−08 −1.2189E−07 −1.2955E−05  1.5380E−05 A16 = — —−1.5224E−08   2.4405E−08  2.5199E−06 −9.3673E−07 A18 = — — —  1.4984E−08−1.4660E−07 — Surface # 8 9 11 12 13 14 k =  2.7191E+00 −4.1782E+01−8.0000E+01 −2.5139E+01 −3.9337E+01 −7.3973E+00 A4 = −2.9874E−03−4.4364E−03 −2.1929E−02  1.2260E−02  9.0922E−03 −2.2031E−02 A6 =−6.0021E−05  1.0978E−03 −2.2859E−03 −2.1963E−02 −5.7658E−03  6.3533E−03A8 = −9.5802E−05 −2.6788E−04  2.8790E−03  8.5705E−03 −4.1173E−03−1.1477E−03 A10 =  3.7966E−05  7.5373E−05 −1.1392E−03 −1.2752E−03 5.4841E−03  5.0289E−04 A12 = −1.1136E−05 −1.6446E−05  2.3471E−04−1.8003E−05 −1.9969E−03 −9.5407E−05 A14 =  1.6255E−06  2.2658E−06−1.7690E−05  1.6110E−05  3.1274E−04  6.3978E−06 A16 = −1.0496E−07−1.3832E−07 — — −1.8366E−05 −3.8403E−07

5TH EMBODIMENT

FIG. 17 is one perspective view of an electronic device according to the5th embodiment of the present disclosure. FIG. 18 is another perspectiveview of the electronic device in FIG. 17. FIG. 19 is a cross-sectionalview of two image capturing units of the electronic device in FIG. 17.

In this embodiment, an electronic device 20 is a smartphone including animage capturing unit 10, an image capturing unit 10 a, an imagecapturing unit 10 b, an image capturing unit 10 c, an image capturingunit 10 d, an image capturing unit 10 e, a flash module 21, a displayunit 22, a focus assist module, an image signal processor and an imagesoftware processor.

In this embodiment, the image capturing unit 10 is a camera moduleincluding a lens unit, a driving device, an image sensor and an imagestabilizer. The lens unit includes the image capturing lens systemdisclosed in the 1st embodiment, a barrel and a holder member. However,the lens unit may alternatively be provided with the image capturinglens system disclosed in other embodiments, and the present disclosureis not limited thereto. In addition, the image capturing unit 10 is atelephoto image capturing unit configured with a light-folding elementLF6, and the light-folding element LF6 is disposed on the object side ofthe first lens element. Therefore, it is favorable for adjusting lighttravelling direction and folding optical axis, so that the total tracklength of the image capturing unit 10 and the thickness of theelectronic device 20 are not restricted by each other. The imaging lightconverges in the lens unit of the image capturing unit 10 to generate animage with the driving device utilized for image zooming or focusing onthe image sensor, and the generated image is then digitally transmittedto other electronic component for further processing.

The driving device can have zooming functionality or auto focusingfunctionality, and different driving configurations can be obtainedthrough the usages of screws, voice coil motors (VCM) such as springtype or ball type, micro electro-mechanical systems (MEMS),piezoelectric systems, or shape memory alloy materials. The drivingdevice is favorable for obtaining a better imaging position of the lensunit, so that a clear image of the imaged object can be captured by thelens unit with different object distances. The image sensor (forexample, CCD or CMOS), which can feature high photosensitivity and lownoise, is disposed on the image surface of the image capturing lenssystem to provide higher image quality.

The image stabilizer, such as an accelerometer, a gyro sensor and a HallEffect sensor, is configured to work with the driving device to provideoptical image stabilization (OIS). The driving device working with theimage stabilizer is favorable for compensating for pan and tilt of thelens unit to reduce blurring associated with motion during exposure. Insome cases, the compensation can be provided by electronic imagestabilization (EIS) with image processing software, thereby improvingimage quality while in motion or low-light conditions.

The image capturing units 10, 10 a, 10 b are disposed on the same sideof the electronic device 20, and the image capturing units 10 c, 10 d,10 e and the display unit 22 are disposed on the opposite side of theelectronic device 20. Each of the image capturing units 10 a, 10 b, 10c, 10 d, 10 e can have a configuration similar to that of the imagecapturing unit 10, so the details in this regard will not be providedagain. The image capturing unit 10 a includes an optical lens assemblyand an image sensor (their reference numerals are omitted). As shown inFIG. 19, the optical lens assembly of the image capturing unit 10 a hasan optical axis OA6, and a movement direction DLG of lens groups of theimage capturing unit 10 is perpendicular to the optical axis OA6;furthermore, the movement direction DLG of lens groups of the imagecapturing unit 10 is also perpendicular to an optical axis of the imagecapturing unit 10 b. Therefore, it is favorable for adjusting spacearrangement so as to reduce the thickness of the electronic device.

The image capturing unit 10 is a telephoto image capturing unitconfigured with a light-folding element, the image capturing unit 10 ais a telephoto image capturing unit, and the image capturing unit 10 bis a wide angle image capturing unit. Half of a maximum field of view ofthe image capturing unit 10 a ranges between 15 degrees and 30 degrees,and half of a maximum field of view of the image capturing unit 10 branges between 30 degrees and 60 degrees. In other configurations, halfof the maximum field of view of the image capturing unit 10 b can rangebetween 35 degrees and 50 degrees. The image capturing units 10, 10 a,10 b have different fields of view, such that the electronic device 20can have a larger zoom ratio for more applications. The abovementionedelectronic device 20 has the three image capturing units 10, 10 a, 10 bon the same side, but the present disclosure is not limited thereto. Inother configurations, the electronic device may have at least two imagecapturing units disposed on the same side or have at least three imagecapturing units disposed on the same side.

The image capturing unit 10 c is a wide angle image capturing unit, theimage capturing unit 10 d is an ultra-wide-angle image capturing unit,and the image capturing unit 10 e is a ToF (time of flight) imagecapturing unit, wherein the image capturing unit 10 e can determinedepth information of the imaged object. The image capturing units 10 c,10 d, 10 e and the display unit 22 are disposed on the same side of theelectronic device 20, such that the image capturing units 10 c, 10 d, 10e can be front-facing cameras of the electronic device 20 for takingselfies, but the present disclosure is not limited thereto.

The electronic device 20 includes multiple image capturing units 10, 10a, 10 b, 10 c, 10 d, 10 e, but the present disclosure is not limited tothe number and arrangement of image capturing units.

When a user captures images of an object, the light rays converge in theimage capturing units 10, 10 a or 10 b to generate an image(s), and theflash module 21 is activated for light supplement. The focus assistmodule detects the object distance of the imaged object to achieve fastauto focusing. The image signal processor is configured to optimize thecaptured image to improve image quality. The light beam emitted from thefocus assist module can be either conventional infrared or laser. Inaddition, the light rays may converge in the image capturing units 10 c,10 d or 10 e to generate an image(s). The display unit 22 can be a touchscreen, and the user is able to interact with the display unit 22 andthe image software processor having multiple functions to capture imagesand complete image processing. Alternatively, the user may captureimages via a physical button. The image processed by the image softwareprocessor can be displayed on the display unit 22.

6TH EMBODIMENT

FIG. 20 is a perspective view of an electronic device according to the6th embodiment of the present disclosure.

In this embodiment, an electronic device 30 is a smartphone including animage capturing unit 10 f, an image capturing unit 10 g, an imagecapturing unit 10 h, an image capturing unit 10 i, an image capturingunit 10 j, an image capturing unit 10 k, an image capturing unit 10 m,an image capturing unit 10 n, an image capturing unit 10 p, a flashmodule 31, a focus assist module, an image signal processor, a displayunit and an image software processor (not shown). The image capturingunits 10 f, 10 g, 10 h, 10 i, 10 j, 10 k, 10 m, 10 n, 10 p are disposedon the same side of the electronic device 30, and the display unit isdisposed on the opposite side of the electronic device 30. Each of theimage capturing units 10 f, 10 g, 10 h, 10 i, 10 j, 10 k, 10 m, 10 n, 10p can include the image capturing lens system of the present disclosureand can have a configuration similar to that of the image capturing unit10, so the details in this regard will not be provided again.

The image capturing units 10 f, 10 g are telephoto image capturing unitsconfigured with light-folding element(s), the image capturing units 10h, 10 i are telephoto image capturing units, the image capturing units10 j, 10 k are wide angle image capturing units, the image capturingunits 10 m, 10 n are ultra-wide-angle image capturing units, and theimage capturing unit 10 p is a ToF image capturing unit. The imagecapturing units 10 f, 10 g with light-folding element(s) mayrespectively have a configuration, for example, similar to that as shownin FIG. 23, FIG. 24 or FIG. 25, and a description in this regard willnot be provided again. In this embodiment, the image capturing units 10f, 10 g, 10 h, 10 i, 10 j, 10 k, 10 m, 10 n, 10 p have different fieldsof view, such that the electronic device 30 has various magnificationratios so as to meet the requirement of optical zoom functionality. Theelectronic device 30 includes multiple image capturing units 10 f, 10 g,10 h, 10 i, 10 j, 10 k, 10 m, 10 n, 10 p, but the present disclosure isnot limited to the number and arrangement of image capturing units.

The smartphone in this embodiment is only exemplary for showing theimage capturing unit of the present disclosure installed in anelectronic device, and the present disclosure is not limited thereto.The image capturing unit can be optionally applied to optical systemswith a movable focus. Furthermore, the image capturing lens system ofthe image capturing unit features good capability in aberrationcorrections and high image quality, and can be applied to 3D(three-dimensional) image capturing applications, in products such asdigital cameras, mobile devices, digital tablets, smart televisions,network surveillance devices, dashboard cameras, vehicle backup cameras,multi-camera devices, image recognition systems, motion sensing inputdevices, wearable devices and other electronic imaging devices.

The foregoing description, for the purpose of explanation, has beendescribed with reference to specific embodiments. It is to be noted thatTABLES 1-12 show different data of the different embodiments; however,the data of the different embodiments are obtained from experiments. Theembodiments were chosen and described in order to best explain theprinciples of the disclosure and its practical applications, to therebyenable others skilled in the art to best utilize the disclosure andvarious embodiments with various modifications as are suited to theparticular use contemplated. The embodiments depicted above and theappended drawings are exemplary and are not intended to be exhaustive orto limit the scope of the present disclosure to the precise formsdisclosed. Many modifications and variations are possible in view of theabove teachings.

What is claimed is:
 1. An image capturing lens system comprising threelens groups, the three lens groups comprising five lens elements, thethree lens groups being, in order from an object side to an image sidealong an optical path, a first lens group, a second lens group and athird lens group, the five lens elements being, in order from the objectside to the image side along the optical path, a first lens element, asecond lens element, a third lens element, a fourth lens element and afifth lens element, and each of the five lens elements having anobject-side surface facing toward the object side and an image-sidesurface facing toward the image side; wherein the first lens groupcomprises the first lens element and the second lens element, the secondlens group comprises the third lens element, the third lens groupcomprises the fourth lens element and the fifth lens element, theobject-side surface of the first lens element is convex in a paraxialregion thereof, the second lens element has negative refractive power,and at least one lens element in the first lens group, the second lensgroup and the third lens group has at least one inflection point in anoff-axis region thereof; wherein a focal length of the image capturinglens system is varied by changing axial distances between the three lensgroups in a zooming process, the image capturing lens system has along-focal-length end and a short-focal-length end, the second lensgroup is moved relative to the first lens group along an optical axis inthe zooming process, and the third lens group is moved relative to thefirst lens group along the optical axis in the zooming process; whereinan Abbe number of one of the five lens elements is Vi, a refractiveindex of the one of the five lens elements is Ni, a minimum value ofVi/Ni is (Vi/Ni) min, half of a maximum field of view of the imagecapturing lens system at the short-focal-length end is HFOVS, a maximumdistance between an optically effective area of the object-side surfaceof the first lens element and the optical axis when the image capturinglens system is at the long-focal-length end is Y11L, a maximum distancebetween an optically effective area of the object-side surface of thefirst lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y11S, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the long-focal-length end is Y52L, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y52S, and the followingconditions are satisfied: 7.5<(Vi/Ni) min<12.3; 5.0 degrees<HFOVS<25.0degrees; 0.50<Y11L/Y52L<2.0; and 0.50<Y11S/Y52S<2.0.
 2. The imagecapturing lens system of claim 1, wherein the maximum distance betweenthe optically effective area of the object-side surface of the firstlens element and the optical axis when the image capturing lens systemis at the long-focal-length end is Y11L, the maximum distance betweenthe optically effective area of the object-side surface of the firstlens element and the optical axis when the image capturing lens systemis at the short-focal-length end is Y11S, the maximum distance betweenthe optically effective area of the image-side surface of the fifth lenselement and the optical axis when the image capturing lens system is atthe long-focal-length end is Y52L, the maximum distance between theoptically effective area of the image-side surface of the fifth lenselement and the optical axis when the image capturing lens system is atthe short-focal-length end is Y52S, a focal length of the imagecapturing lens system at the long-focal-length end is fL, a focal lengthof the image capturing lens system at the short-focal-length end is fS,and the following conditions are satisfied: 0.55<Y11L/Y52L<1.8;0.55<Y11S/Y52S<1.8; and 1.45<fL/fS.
 3. The image capturing lens systemof claim 1, wherein an Abbe number of the third lens element is V3, anAbbe number of the fourth lens element is V4, and the followingcondition is satisfied: 1.5<V3/V4<5.0.
 4. The image capturing lenssystem of claim 1, wherein a curvature radius of the object-side surfaceof the fifth lens element is R9, a curvature radius of the image-sidesurface of the fifth lens element is R10, and the following condition issatisfied: 0.10<(R9+R10)/(R9−R10)<5.0.
 5. The image capturing lenssystem of claim 1, wherein a focal length of the first lens element isf1, a focal length of the second lens element is f2, and the followingcondition is satisfied: |f2/f1|<1.5.
 6. The image capturing lens systemof claim 1, wherein the third lens element has positive refractivepower, a focal length of the second lens element is f2, a focal lengthof the third lens element is f3, and the following condition issatisfied: −2.0<f2/f3<−0.60.
 7. The image capturing lens system of claim1, wherein at least one lens element in the first lens group, the secondlens group and the third lens group is made of plastic material, themaximum distance between the optically effective area of the object-sidesurface of the first lens element and the optical axis when the imagecapturing lens system is at the long-focal-length end is Y11L, themaximum distance between the optically effective area of the object-sidesurface of the first lens element and the optical axis when the imagecapturing lens system is at the short-focal-length end is Y11S, amaximum image height of the image capturing lens system at thelong-focal-length end is ImgHL, a maximum image height of the imagecapturing lens system at the short-focal-length end is ImgHS, and thefollowing conditions are satisfied: 0.50<Y11L/ImgHL<2.7; and0.50<Y11S/ImgHS<2.7.
 8. The image capturing lens system of claim 1,wherein the image capturing lens system focuses on an object in afocusing process as an object distance varies, and the third lens groupis moved relative to the first lens group along the optical axis in thefocusing process.
 9. An image capturing lens system comprising threelens groups, the three lens groups comprising five lens elements, thethree lens groups being, in order from an object side to an image sidealong an optical path, a first lens group, a second lens group and athird lens group, the five lens elements being, in order from the objectside to the image side along the optical path, a first lens element, asecond lens element, a third lens element, a fourth lens element and afifth lens element, and each of the five lens elements having anobject-side surface facing toward the object side and an image-sidesurface facing toward the image side; wherein the object-side surface ofthe first lens element is convex in a paraxial region thereof, thesecond lens element has negative refractive power, and at least one lenselement in the first lens group, the second lens group and the thirdlens group has at least one inflection point in an off-axis regionthereof; wherein a focal length of the image capturing lens system isvaried by changing axial distances between the three lens groups in azooming process, the image capturing lens system has a long-focal-lengthend and a short-focal-length end, the second lens group is movedrelative to the first lens group along an optical axis in the zoomingprocess, and the third lens group is moved relative to the first lensgroup along the optical axis in the zooming process; wherein an Abbenumber of one of the five lens elements is Vi, a refractive index of theone of the five lens elements is Ni, a minimum value of Vi/Ni is (Vi/Ni)min, half of a maximum field of view of the image capturing lens systemat the short-focal-length end is HFOVS, a maximum distance between anoptically effective area of the object-side surface of the first lenselement and the optical axis when the image capturing lens system is atthe long-focal-length end is Y11L, a maximum distance between anoptically effective area of the object-side surface of the first lenselement and the optical axis when the image capturing lens system is atthe short-focal-length end is Y11S, a maximum distance between anoptically effective area of the image-side surface of the fifth lenselement and the optical axis when the image capturing lens system is atthe long-focal-length end is Y52L, a maximum distance between anoptically effective area of the image-side surface of the fifth lenselement and the optical axis when the image capturing lens system is atthe short-focal-length end is Y52S, an axial distance between theobject-side surface of the first lens element and an image surface whenthe image capturing lens system is at the long-focal-length end is TLL,an axial distance between the object-side surface of the first lenselement and the image surface when the image capturing lens system is atthe short-focal-length end is TLS, and the following conditions aresatisfied: 7.5<(Vi/Ni) min<12.3; 5.0 degrees<HFOVS<25.0 degrees;0.50<Y11L/Y52L<2.0; 0.50<Y11S/Y52S<2.0; and |TLL/TLS−1|<1.0E−2.
 10. Theimage capturing lens system of claim 9, wherein a focal length of theimage capturing lens system at the long-focal-length end is fL, a focallength of the image capturing lens system at the short-focal-length endis fS, and the following condition is satisfied: 1.45<fL/fS<3.10. 11.The image capturing lens system of claim 9, wherein an axial distancebetween a most object-side surface and a most image-side surface of thefirst lens group is TG1, an axial distance between a most object-sidesurface and a most image-side surface of the third lens group is TG3,and the following condition is satisfied: 0.50<TG1/TG3<2.0.
 12. Theimage capturing lens system of claim 9, wherein a focal length of thesecond lens group is fG2, a focal length of the third lens group is fG3,and the following condition is satisfied: |fG2/fG3|<0.60.
 13. The imagecapturing lens system of claim 9, wherein the image-side surface of thesecond lens element is concave in a paraxial region thereof, the thirdlens element has positive refractive power, and the object-side surfaceof the third lens element is convex in a paraxial region thereof. 14.The image capturing lens system of claim 9, wherein the first lens grouphas negative refractive power, the second lens group has positiverefractive power, a focal length of the first lens group is fG1, a focallength of the second lens group is fG2, and the following condition issatisfied: −7.0<fG1/fG2<−0.80.
 15. The image capturing lens system ofclaim 9, wherein each of at least two lens elements in the first lensgroup, the second lens group and the third lens group has at least oneinflection point in an off-axis region thereof, the axial distancebetween the object-side surface of the first lens element and the imagesurface when the image capturing lens system is at the long-focal-lengthend is TLL, the axial distance between the object-side surface of thefirst lens element and the image surface when the image capturing lenssystem is at the short-focal-length end is TLS, a maximum image heightof the image capturing lens system at the long-focal-length end isImgHL, a maximum image height of the image capturing lens system at theshort-focal-length end is ImgHS, and the following conditions aresatisfied: 8.0<TLL/ImgHL<15; and 8.0<TLS/ImgHS<15.
 16. The imagecapturing lens system of claim 9, wherein the second lens group is movedalong the optical axis toward the object side relative to the first lensgroup when the image capturing lens system is zooming from theshort-focal-length end to the long-focal-length end, an axial distancebetween the first lens group and the second lens group when the imagecapturing lens system is at the long-focal-length end is TG12L, an axialdistance between the first lens group and the second lens group when theimage capturing lens system is at the short-focal-length end is TG12S,an axial distance between a most object-side surface and a mostimage-side surface of the second lens group is TG2, and the followingcondition is satisfied: −6.0<(TG12L-TG12S)/TG2<−1.2.
 17. An imagecapturing lens system comprising three lens groups, the three lensgroups comprising five lens elements, the three lens groups being, inorder from an object side to an image side along an optical path, afirst lens group, a second lens group and a third lens group, the fivelens elements being, in order from the object side to the image sidealong the optical path, a first lens element, a second lens element, athird lens element, a fourth lens element and a fifth lens element, andeach of the five lens elements having an object-side surface facingtoward the object side and an image-side surface facing toward the imageside; wherein the object-side surface of the first lens element isconvex in a paraxial region thereof, the second lens element hasnegative refractive power, and at least one lens element in the firstlens group, the second lens group and the third lens group has at leastone inflection point in an off-axis region thereof; wherein a focallength of the image capturing lens system is varied by changing axialdistances between the three lens groups in a zooming process, the imagecapturing lens system has a long-focal-length end and ashort-focal-length end, and the second lens group is moved relative tothe first lens group along an optical axis in the zooming process;wherein an Abbe number of one of the five lens elements is Vi, arefractive index of the one of the five lens elements is Ni, a minimumvalue of Vi/Ni is (Vi/Ni) min, half of a maximum field of view of theimage capturing lens system at the short-focal-length end is HFOVS, amaximum distance between an optically effective area of the object-sidesurface of the first lens element and the optical axis when the imagecapturing lens system is at the long-focal-length end is Y11L, a maximumdistance between an optically effective area of the object-side surfaceof the first lens element and the optical axis when the image capturinglens system is at the short-focal-length end is Y11S, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the long-focal-length end is Y52L, a maximum distancebetween an optically effective area of the image-side surface of thefifth lens element and the optical axis when the image capturing lenssystem is at the short-focal-length end is Y52S, and the followingconditions are satisfied: 7.5<(Vi/Ni) min<12.3; 7.5 degrees<HFOVS<20.0degrees; 0.50<Y11L/Y52L<2.0; and 0.50<Y11S/Y52S<2.0.
 18. The imagecapturing lens system of claim 17, wherein half of a maximum field ofview of the image capturing lens system at the long-focal-length end isHFOVL, half of the maximum field of view of the image capturing lenssystem at the short-focal-length end is HFOVS, a focal length of theimage capturing lens system at the long-focal-length end is fL, a focallength of the image capturing lens system at the short-focal-length endis fS, and the following conditions are satisfied: 3.0degrees<HFOVL<10.0 degrees; 10.0 degrees<HFOVS<15.0 degrees; and1.45<fL/fS.
 19. The image capturing lens system of claim 17, wherein anaxial distance between a most object-side surface and a most image-sidesurface of the second lens group is TG2, an axial distance between amost object-side surface and a most image-side surface of the third lensgroup is TG3, and the following condition is satisfied:0.40<TG2/TG3<2.0.
 20. The image capturing lens system of claim 17,wherein a focal length of the third lens group is fG3, an axial distancebetween the image-side surface of the fifth lens element and an imagesurface when the image capturing lens system is at the long-focal-lengthend is BLL, an axial distance between the image-side surface of thefifth lens element and the image surface when the image capturing lenssystem is at the short-focal-length end is BLS, and the followingcondition is satisfied: fG3/(BLL-BLS)<−1.5.
 21. The image capturing lenssystem of claim 17, wherein the third lens element has positiverefractive power, the object-side surface of the third lens element isconvex in a paraxial region thereof, the image-side surface of the thirdlens element is convex in a paraxial region thereof, a curvature radiusof the object-side surface of the third lens element is R5, a curvatureradius of the image-side surface of the third lens element is R6, andthe following condition is satisfied: −1.0<(R5+R6)/(R5−R6)<0.
 22. Theimage capturing lens system of claim 17, wherein the first lens grouphas negative refractive power, the second lens group has positiverefractive power, a focal length of the image capturing lens system atthe short-focal-length end is fS, a focal length of the first lens groupis fG1, a focal length of the second lens group is fG2, a focal lengthof the third lens group is fG3, and the following conditions aresatisfied: −1.8<fS/fG1<−0.45; 0.70<fS/fG2<2.4; and −0.70<fS/fG3<0.70.23. The image capturing lens system of claim 17, further comprising anaperture stop and a light-folding element, wherein the aperture stop isdisposed in the second lens group.
 24. The image capturing lens systemof claim 17, wherein at least one lens element in the second lens groupand the third lens group has at least one critical point in an off-axisregion thereof, an axial distance between the object-side surface of thefirst lens element and an image surface when the image capturing lenssystem is at the long-focal-length end is TLL, a focal length of theimage capturing lens system at the long-focal-length end is fL, anf-number of the image capturing lens system at the short-focal-lengthend is FnoS, and the following conditions are satisfied:0.80<TLL/fL<1.8; and 2.2<FnoS<3.8.
 25. An image capturing unit,comprising: the image capturing lens system of claim 17; and an imagesensor disposed on an image surface of the image capturing lens system.26. An electronic device, comprising at least two image capturing unitslocated on a same side of the electronic device, and the at least twoimage capturing units comprising: a first image capturing unit,comprising the image capturing lens system of claim 17 and an imagesensor disposed on an image surface of the image capturing lens system;and a second image capturing unit, comprising an optical lens assemblyand an image sensor disposed on an image surface of the optical lensassembly; wherein half of a maximum field of view of the second imagecapturing unit ranges between 30 degrees and 60 degrees.